There is no curative treatment for this condition. Supportive management is helpful.

Due to the progressive, continuous nature of the disease, improvement over time seldom occurs in patients with PPA as it often does in patients with aphasias caused by trauma to the brain.

In terms of medical approaches to treating PPA, there are currently no drugs specifically used for patients with PPA, nor are there any specifically designed interventions for PPA. A large reason for this is the limited research that has been done on this disease. However, in some cases, patients with PPA are prescribed the same drugs Alzheimer's patients are normally prescribed.

The primary approach to treating PPA has been with behavioral treatment, with the hope that these methods can provide new ways for patients to communicate in order to compensate for their deteriorated abilities. Speech therapy can assist an individual with strategies to overcome difficulties. There are three very broad categories of therapy interventions for aphasia: restorative therapy approaches, compensatory therapy approaches, and social therapy approaches. Rapid and sustained improvement in speech and dementia in a patient with primary progressive aphasia utilizing off-label perispinal etanercept, an anti-TNF treatment strategy also used for Alzheimer's, has been reported. A video depicting the patient's improvement was published in conjunction with the print article. These findings have not been independently replicated and remain controversial.

The intensity of aphasia therapy is determined by the length of each session, total hours of therapy per week, and total weeks of therapy provided. There is no consensus about what “intense” aphasia therapy entails, or how intense therapy should be to yield the best outcomes. A 2016 Cochrane review of speech and language therapy for people with aphasia found that treatments that are higher intensity, higher dose or over a long duration of time led to significantly better functional communication but people were more likely to drop out of high intensity treatment (up to 15 hours per week).

Intensity of therapy is also dependent on the recency of stroke. People with aphasia react differently to intense treatment in the acute phase (0–3 months post stroke), sub-acute phase (3–6 months post stroke), or chronic phase (6+ months post stroke). Intensive therapy has been found to be effective for people with nonfluent and fluent chronic aphasia, but less effective for people with acute aphasia.> People with sub-acute aphasia also respond well to intensive therapy of 100 hours over 62 weeks. This suggests people in the sub-acute phase can improve greatly in language and functional communication measures with intensive therapy compared to regular therapy.

When addressing Wernicke’s aphasia, according to Bakheit et al. (2007), the lack of awareness of the language impairments, a common characteristic of Wernicke’s aphasia, may impact the rate and extent of therapy outcomes. Klebic et al. (2011) suggests that people benefit from continuing therapy upon discharge from the hospital to ensure generalization. Robey (1998) determined that at least 2 hours of treatment per week is recommended for making significant language gains. Spontaneous recovery may cause some language gains, but without speech-language therapy, the outcomes can be half as strong as those with therapy.

When addressing Broca’s aphasia, better outcomes occur when the person participates in therapy, and treatment is more effective than no treatment for people in the acute period. Two or more hours of therapy per week in acute and post-acute stages produced the greatest results. High intensity therapy was most effective, and low intensity therapy was almost equivalent to no therapy.

People with global aphasia are sometimes referred to as having irreversible aphasic syndrome, often making limited gains in auditory comprehension, and recovering no functional language modality with therapy. With this said, people with global aphasia may retain gestural communication skills that may enable success when communicating with conversational partners within familiar conditions. Process-oriented treatment options are limited, and people may not become competent language users as readers, listeners, writers, or speakers no matter how extensive therapy is. However, people’s daily routines and quality of life can be enhanced with reasonable and modest goals. After the first month, there is limited to no healing to language abilities of most people. There is a grim prognosis leaving 83% who were globally aphasic after the first month they will remain globally aphasic at the first year. Some people are so severely impaired that their existing process-oriented treatment approaches offer signs of progress, and therefore cannot justify the cost of therapy.

Perhaps due to the relative rareness of conduction aphasia, few studies have specifically studied the effectiveness of therapy for people with this type of aphasia. From the studies performed, results showed that therapy can help to improve specific language outcomes. One intervention that has had positive results is auditory repetition training. Kohn et al. (1990) reported that drilled auditory repetition training related to improvements in spontaneous speech, Francis et al. (2003) reported improvements in sentence comprehension, and Kalinyak-Fliszar et al. (2011) reported improvements in auditory-visual short-term memory.

Most acute cases of aphasia recover some or most skills by working with a speech-language pathologist. Recovery and improvement can continue for years after the stroke. After the onset of Aphasia, there is approximately a six-month period of spontaneous recovery; during this time, the brain is attempting to recover and repair the damaged neurons. Improvement varies widely, depending on the aphasia's cause, type, and severity. Recovery also depends on the person's age, health, motivation, handedness, and educational level.

There is no one treatment proven to be effective for all types of aphasias. The reason that there is no universal treatment for aphasia is because of the nature of the disorder and the various ways it is presented, as explained in the above sections. Aphasia is rarely exhibited identically, implying that treatment needs to be catered specifically to the individual. Studies have shown that, although there is no consistency on treatment methodology in literature, there is a strong indication that treatment in general has positive outcomes. Therapy for aphasia ranges from increasing functional communication to improving speech accuracy, depending on the person's severity, needs and support of family and friends. Group therapy allows individuals to work on their pragmatic and communication skills with other individuals with aphasia, which are skills that may not often be addressed in individual one-on-one therapy sessions. It can also help increase confidence and social skills in a comfortable setting.

Evidence dose not support the use of transcranial direct current stimulation (tDCS) for improving aphasia after stroke.

Specific treatment techniques include the following:

- Copy and Recall Therapy (CART) - repetition and recall of targeted words within therapy may strengthen orthographic representations and improve single word reading, writing, and naming

- Visual Communication Therapy (VIC) - the use of index cards with symbols to represent various components of speech

- Visual Action Therapy (VAT) - typically treats individuals with global aphasia to train the use of hand gestures for specific items

- Functional Communication Treatment (FCT) - focuses on improving activities specific to functional tasks, social interaction, and self-expression

- Promoting Aphasic's Communicative Effectiveness (PACE) - a means of encouraging normal interaction between people with aphasia and clinicians. In this kind of therapy the focus is on pragmatic communication rather than treatment itself. People are asked to communicate a given message to their therapists by means of drawing, making hand gestures or even pointing to an object

- Melodic Intonation Therapy (MIT) - aims to use the intact melodic/prosodic processing skills of the right hemisphere to help cue retrieval of words and expressive language

- Other - i.e. drawing as a way of communicating, trained conversation partners

Semantic feature analysis (SFA) -a type of aphasia treatment that targets word-finding deficits. It is based on the theory that neural connections can strengthened by using using related words and phrases that are similar to the target word, to eventually activate the target word in the brain. SFA can be implemented in multiple forms such as verbally, written, using picture cards, etc. The SLP provides prompting questions to the individual with aphasia in order for the person to name the picture provided. Studies show that SFA is an effective intervention for improving confrontational naming.

Melodic intonation therapy is used to treat non-fluent aphasia and has proved to be effective in some cases. However, there is still no evidence from randomized controlled trials confirming the efficacy of MIT in chronic aphasia. MIT is used to help people with aphasia vocalize themselves through speech song, which is then transferred as a spoken word. Good candidates for this therapy include people who have had left hemisphere strokes, non-fluent aphasias such as Broca's, good auditory comprehension, poor repetition and articulation, and good emotional stability and memory. An alternative explanation is that the efficacy of MIT depends on neural circuits involved in the processing of rhythmicity and formulaic expressions (examples taken from the MIT manual: “I am fine,” “how are you?” or “thank you”); while rhythmic features associated with melodic intonation may engage primarily left-hemisphere subcortical areas of the brain, the use of formulaic expressions is known to be supported by right-hemisphere cortical and bilateral subcortical neural networks.

According to the National Institute on Deafness and Other Communication Disorders (NIDCD), involving family with the treatment of an Aphasic loved one is ideal for all involved, because while it will no doubt assist in their recovery, it will also make it easier for members of the family to learn how best to communicate with them.

There is currently no known curative treatment for SD. The average duration of illness is 8–10 years, and its progression cannot be slowed. Progression of SD can lead to behavioral and social difficulties, thus supportive care is essential for improving quality of life in SD patients as they grow more incomprehensible.

Continuous practice in lexical learning has been shown to improve semantic memory in SD patients.

SD has no known preventative measures.

Currently, the specific causes for PPA and other degenerative brain disease similar to PPA are unknown. Autopsies have revealed a variety of brain abnormalities in people who had PPA. These autopsies, as well as imaging techniques such as CT scans, MRI, EEG, single photon emission computed tomography (SPECT), and positron emission tomography (PET), have generally revealed abnormalities to be almost exclusively in the left hemisphere.

Semantic dementia (SD), also known as semantic variant primary progressive aphasia (svPPA), is a progressive neurodegenerative disorder characterized by loss of semantic memory in both the verbal and non-verbal domains. However, the most common presenting symptoms are in the verbal domain (with loss of word meaning). SD is one of the three canonical clinical syndromes associated with frontotemporal lobar degeneration (FTLD), with the other two being frontotemporal dementia and progressive nonfluent aphasia. SD is a clinically defined syndrome, but is associated with predominantly temporal lobe atrophy (left greater than right) and hence is sometimes called temporal variant FTLD (tvFTLD). SD is one of the three variants of Primary Progressive Aphasia (PPA), which results from neurodegenerative disorders such as FTLD or Alzheimer's disease. It is important to note the distinctions between Alzheimer’s Disease and Semantic dementia with regard to types of memory affected. In general, Alzheimer’s Disease is referred to as disorder affecting mainly episodic memory, defined as the memory related to specific, personal events distinct for each individual. Semantic dementia generally affects semantic memory, which refers to long-term memory that deals with common knowledge and facts.3

It was first described by Arnold Pick in 1904 and in modern times was characterized by Professor Elizabeth Warrington in 1975, but it was not given the name semantic dementia until 1989. The clinical and neuropsychological features, and their association with temporal lobe atrophy were described by Professor John Hodges and colleagues in 1992.

Logopenic progressive aphasia (LPA) is a form of primary progressive aphasia. It is defined clinically by impairments in naming and sentence repetition. It is similar to conduction aphasia and is associated with atrophy to the left posterior temporal cortex and inferior parietal lobule. It is suspected that an atypical form of Alzheimer's disease is the most common cause of logopenic progressive aphasia.

Although patients with the logopenic variant of PPA are still able to produce speech, their speech rate may be significantly slowed down due to word retrieval difficulty. Over time, they may experience the inability to retain lengthy information, causing problems with understanding complex verbal information. Some additional behavioral features include irritability, anxiety and agitation.

Compared to other forms of primary progressive aphasia, the logopenic variant has been found to be associated with cognitive and behavioral characteristics. Studies have shown that patients with the logopenic variant perform significantly worse on tests of calculation than other primary progressive aphasia patients. Several logopenic variant patients, especially those with Alzheimer’s disease pathology, have also been found to perform poorly on memory tasks.

Logopenic progressive aphasia is caused by damage to segregated brain regions, specifically the inferior parietal lobe and superior temporal regions. Difficulties in naming are produced from the thinning of the inferior parietal lobe. Damage to the dorsal pathways creates language deficiency in patients that is characteristic of logopenic progressive aphasia.

Progressive nonfluent aphasia (PNFA) is one of three clinical syndromes associated with frontotemporal lobar degeneration. PNFA has an insidious onset of language deficits over time as opposed to other stroke-based aphasias, which occur acutely following trauma to the brain. The specific degeneration of the frontal and temporal lobes in PNFA creates hallmark language deficits differentiating this disorder from other Alzheimer-type disorders by the initial absence of other cognitive and memory deficits. This disorder commonly has a primary effect on the left hemisphere, causing the symptomatic display of expressive language deficits (production difficulties) and sometimes may disrupt receptive abilities in comprehending grammatically complex language.

There is no known cure for PSP and management is primarily supportive. PSP cases are often split into two subgroups, PSP-Richardson, the classic type, and PSP-Parkinsonism, where a short-term response to levodopa can be obtained. Dyskinesia is an occasional but rare complication of treatment. Amantadine is also sometimes helpful. After a few years the Parkinsonian variant tends to take on Richardson features. Other variants have been described. Botox can be used to treat neck dystonia and blephrospasm, but this can aggravate dysphagia.

Two studies have suggested that rivastigmine may help with cognitive aspects, but the authors of both studies have suggested a larger sampling be used. There is some evidence that the hypnotic zolpidem may improve motor function and eye movements, but only from small-scale studies.

Patients with PSP usually seek or are referred to occupational therapy, speech-language pathology for motor speech changes typically a spastic-ataxic dysarthria, and physical therapy for balance and gait problems with reports of frequent falls. Evidence-based approaches to rehabilitation in PSP are lacking, and currently the majority of research on the subject consists of case reports involving only a small number of patients.

Case reports of rehabilitation programs for patients with PSP generally include limb-coordination activities, tilt-board balancing, gait training, strength training with progressive resistive exercises and isokinetic exercises and stretching of the neck muscles. While some case reports suggest that physiotherapy can offer improvements in balance and gait of patients with PSP, the results cannot be generalized across all patients with PSP as each case report only followed one or two patients. The observations made from these case studies can be useful, however, in helping to guide future research concerning the effectiveness of balance and gait training programs in the management of PSP.

Individuals with PSP are often referred to occupational therapists to help manage their condition and to help enhance their independence. This may include being taught to use mobility aids. Due to their tendency to fall backwards, the use of a walker, particularly one that can be weighted in the front, is recommended over a cane. The use of an appropriate mobility aid will help to decrease the individual’s risk of falls and make them safer to ambulate independently in the community.

Due to their balance problems and irregular movements individuals will need to spend time learning how to safely transfer in their homes as well as in the community. This may include rising from and sitting in chairs safely.

Due to the progressive nature of this disease, all individuals eventually lose their ability to walk and will need to progress to using a wheelchair. Severe dysphagia often follows, and at this point death is often a matter of months.

Visual agnosia is an impairment in recognition of visually presented objects. It is not due to a deficit in vision (acuity, visual field, and scanning), language, memory, or low intellect. While cortical blindness results from lesions to primary visual cortex, visual agnosia is often due to damage to more anterior cortex such as the posterior occipital and/or temporal lobe(s) in the brain. There are two types of visual agnosia: apperceptive agnosia and associative agnosia.

Recognition of visual objects occurs at two primary levels. At an apperceptive level, the features of the visual information from the retina are put together to form a perceptual representation of an object. At an associative level, the meaning of an object is attached to the perceptual representation and the object is identified. If a person is unable to recognize objects because they cannot perceive correct forms of the objects, although their knowledge of the objects is intact (i.e. they do not have anomia), they have apperceptive agnosia. If a person correctly perceives the forms and has knowledge of the objects, but cannot identify the objects, they have associative agnosia.

While most cases of visual agnosia are seen in older adults who have experienced extensive brain damage, there are also cases of young children with less brain damage during developmental years acquiring the symptoms. Commonly, visual agnosia presents as an inability to recognize an object in the absence of other explanations, such as blindness or partial blindness, anomia, memory loss, etc.. Other common manifestations of visual agnosia that are generally tested for include difficulty identifying objects that look similar in shape, difficulty with identifying line drawings of objects, and recognizing objects that are shown from less common views, such as a horse from a top-down view.

Within any given patient, a variety of symptoms can occur, and the impairment of ability is not only binary but can range in severity. For example, Patient SM is a prosopagnosic with a unilateral lesion to left extrastriate cortex due to an accident in his twenties who displays behavior similar to congenital prosopagnosia. Although he can recognize facial features and emotions – indeed he sometimes uses a standout feature to recognize a face – face recognition is almost impossible purely from visual stimuli, even for faces of friends, family, and himself. The disorder also affects his memory of faces, both in storing new memories of faces and recalling stored memories.

Nevertheless, it is important to note the reach of symptoms to other domains. SM’s object recognition is similarly impaired though not entirely; when given line drawings to identify, he was able to give names of objects with properties similar to the drawing, implying that he is able to see the features of the drawing. Similarly, copying a line drawing of a beach scene led to a simplified version of the drawing, though the main features were accounted for. For recognition of places, he is still impaired but familiar places are remembered and new places can be stored into memory.

If suspected antenatally, a consultation with a paediatric surgeon/ paediatric urologist maybe indicated to evaluate the risk and consider treatment options.

Treatment is by endoscopic valve ablation. Fetal surgery is a high risk procedure reserved for cases with severe oligohydramnios, to try to limit the associated lung underdevelopment, or pulmonary hypoplasia, that is seen at birth in these patients. The risks of fetal surgery are significant and include limb entrapment, abdominal injury, and fetal or maternal death. Specific procedures for "in utero" intervention include infusions of amniotic fluid, serial bladder aspiration, and creating a connection between the amniotic sac and the fetal bladder, or vesicoamniotic shunt.

There are three specific endoscopic treatments of posterior urethral valves:

- Vesicostomy followed by valve ablation - a stoma, or hole, is made in the urinary bladder, also known as "low diversion", after which the valve is ablated and the stoma is closed.

- Pyelostomy followed by valve ablation - stoma is made in the pelvis of the kidney as a slightly "high diversion", after which the valve is ablated and the stoma is closed

- Primary (transurethral) valve ablation - the valve is removed through the urethra without creation of a stoma

The standard treatment is primary (transurethral) ablation of the valves. Urinary diversion is used in selected cases, and its benefit is disputed.

Following surgery, the follow-up in patients with posterior urethral valve syndrome is long term, and often requires a multidisciplinary effort between paediatric surgeons/ paediatric urologists, pulmonologists, neonatologists, radiologists and the family of the patient. Care must be taken to promote proper bladder compliance and renal function, as well as to monitor and treat the significant lung underdevelopment that can accompany the disorder. Definitive treatment may also be indicated for the vesico-ureteral reflux.

Courses of treatment for children with is dependent upon the severity of their case. Children with OHS often receive physical and occupational therapy. They may require a feeding tube to supplement nourishment if they are not growing enough. In an attempt to improve the neurological condition (seizures) copper histidine or copper chloride injections can be given early in the child’s life.

However, copper histidine injections have been shown ineffective in studies of copper metabolic-connective tissue disorders such as OHS.

Penetrating karatoplasty and endothelial keratoplasty can be used as treatments for severe cases of ICE [2,8]. Because glaucoma and elevated intraocular pressure are often present in ICE patients, long term follow up may be needed to ensure adequate intraocular pressures are maintained [2,7]

There is no treatment currently available. The virus generally resolves itself within a five to seven day period. The use of steroids can actually cause a corneal microbial superinfection which then requires antimicrobial therapy to eliminate.

In common forms of MTHFR deficiency, elevated plasma homocysteine levels have sometimes been treated with Vitamin B12 and low doses of folic acid. Although this treatment significantly decreases the serum levels of homocysteine, this treatment is not thought to improve health outcomes.

Due to the ineffectiveness of these treatments, it is no-longer considered clinically useful to test for MTHFR in most cases of thrombophilia or recurrent pregnancy loss.

If a patient is resistant to either cladribine or pentostatin, then second-line therapy is pursued.

Monoclonal antibodies The most common treatment for cladribine-resistant disease is infusing monoclonal antibodies that destroy cancerous B cells. Rituximab is by far the most commonly used. Most patients receive one IV infusion over several hours each week for four to eight weeks. A 2003 publication found two partial and ten complete responses out of 15 patients with relapsed disease, for a total of 80% responding. The median patient (including non-responders) did not require further treatment for more than three years. This eight-dose study had a higher response rate than a four-dose study at Scripps, which achieved only 25% response rate. Rituximab has successfully induced a complete response in Hairy Cell-Variant.

Rituximab's major side effect is serum sickness, commonly described as an "allergic reaction", which can be severe, especially on the first infusion. Serum sickness is primarily caused by the antibodies clumping during infusion and triggering the complement cascade. Although most patients find that side effects are adequately controlled by anti-allergy drugs, some severe, and even fatal, reactions have occurred. Consequently, the first dose is always given in a hospital setting, although subsequent infusions may be given in a physician's office. Remissions are usually shorter than with the preferred first-line drugs, but hematologic remissions of several years' duration are not uncommon.

Other B cell-destroying monoclonal antibodies such as Alemtuzumab, Ibritumomab tiuxetan and I-131 Tositumomab may be considered for refractory cases.

Interferon-alpha Interferon-alpha is an immune system hormone that is very helpful to a relatively small number of patients, and somewhat helpful to most patients. In about 65% of patients, the drug helps stabilize the disease or produce a slow, minor improvement for a partial response.

The typical dosing schedule injects at least 3 million units of Interferon-alpha (not pegylated versions) three times a week, although the original protocol began with six months of daily injections.

Some patients tolerate IFN-alpha very well after the first couple of weeks, while others find that its characteristic flu-like symptoms persist. About 10% of patients develop a level of depression. It is possible that, by maintaining a steadier level of the hormone in the body, that daily injections might cause fewer side effects in selected patients. Drinking at least two liters of water each day, while avoiding caffeine and alcohol, can reduce many of the side effects.

A drop in blood counts is usually seen during the first one to two months of treatment. Most patients find that their blood counts get worse for a few weeks immediately after starting treatment, although some patients find their blood counts begin to improve within just two weeks.

It typically takes six months to figure out whether this therapy is useful. Common criteria for treatment success include:

- normalization of hemoglobin levels (above 12.0 g/dL),

- a normal or somewhat low platelet count (above 100 K/µL), and

- a normal or somewhat low absolute neutrophil count (above 1.5 K/µL).

If it is well tolerated, patients usually take the hormone for 12 to 18 months. An attempt may be made then to end the treatment, but most patients discover that they need to continue taking the drug for it to be successful. These patients often continue taking this drug indefinitely, until either the disease becomes resistant to this hormone, or the body produces an immune system response that limits the drug's ability to function. A few patients are able to achieve a sustained clinical remission after taking this drug for six months to one year. This may be more likely when IFN-alpha has been initiated shortly after another therapy. Interferon-alpha is considered the drug of choice for pregnant women with active HCL, although it carries some risks, such as the potential for decreased blood flow to the placenta.

Interferon-alpha works by sensitizing the hairy cells to the killing effect of the immune system hormone TNF-alpha, whose production it promotes. IFN-alpha works best on classic hairy cells that are not protectively adhered to vitronectin or fibronectin, which suggests that patients who encounter less fibrous tissue in their bone marrow biopsies may be more likely to respond to Interferon-alpha therapy. It also explains why non-adhered hairy cells, such as those in the bloodstream, disappear during IFN-alpha treatment well before reductions are seen in adhered hairy cells, such as those in the bone marrow and spleen.

Several treatments are available, and successful control of the disease is common.

Not everyone needs treatment immediately. Treatment is usually given when the symptoms of the disease interfere with the patient's everyday life, or when white blood cell or platelet counts decline to dangerously low levels, such as an absolute neutrophil count below one thousand cells per microliter (1.0 K/uL). Not all patients need treatment immediately upon diagnosis.

Treatment delays are less important than in solid tumors. Unlike most cancers, treatment success does not depend on treating the disease at an early stage. Because delays do not affect treatment success, there are no standards for how quickly a patient should receive treatment. However, waiting too long can cause its own problems, such as an infection that might have been avoided by proper treatment to restore immune system function. Also, having a higher number of hairy cells at the time of treatment can make certain side effects somewhat worse, as some side effects are primarily caused by the body's natural response to the dying hairy cells. This can result in the hospitalization of a patient whose treatment would otherwise be carried out entirely at the hematologist's office.

Single-drug treatment is typical. Unlike most cancers, only one drug is normally given to a patient at a time. While monotherapy is normal, combination therapy—typically using one first-line therapy and one second-line therapy—is being studied in current clinical trials and is used more frequently for refractory cases. Combining rituximab with cladribine or pentostatin may or may not produce any practical benefit to the patient. Combination therapy is almost never used with a new patient. Because the success rates with purine analog monotherapy are already so high, the additional benefit from immediate treatment with a second drug in a treatment-naïve patient is assumed to be very low. For example, one round of either cladribine or pentostatin gives the median first-time patient a decade-long remission; the addition of rituximab, which gives the median patient only three or four years, might provide no additional value for this easily treated patient. In a more difficult case, however, the benefit from the first drug may be substantially reduced and therefore a combination may provide some benefit.

Patients presenting with this disease undergo antibiotic treatment and gammaglobulin transfusions. Antibiotics are used to fight off the pathogenic organisms and the gammaglobulin helps provide a normal balance of antibodies to fight the infection. Bone marrow transplantation may be an option in some cases.

OMIM: 308230

The disease is chronic and often progresses slowly. Prognosis is generally poor when associated with glaucoma [1,2].

Variant Creutzfeldt–Jakob disease (vCJD) or new variant Creutzfeldt–Jakob disease (nvCJD) is a transmissible spongiform encephalopathy which was identified in 1996 by the National CJD Surveillance Unit in Edinburgh, Scotland. It is always fatal and is caused by prions, which are mis-folded proteins. Over 170 cases of vCJD have been recorded in the United Kingdom, and around 30 cases in the rest of the world. The fact that the epidemiology of the disease coincided with an epidemic of bovine spongiform encephalopathy led to the hypothesis that consumption of BSE-infected beef caused the disease. It is a different disease from Sporadic and Familial Creutzfeldt–Jakob disease, though it is believed to be caused by the same pathogenic agent, a mis-folded protein, known as a prion.

Despite the consumption of contaminated beef in the UK being reckoned to be quite high, vCJD has infected a comparatively small cohort of people. One explanation for this can be found in the genetics of patients with the disease. The human PRNP protein which is subverted in prion disease can occur with either methionine or valine at amino acid 129, without any apparent difference in normal function. Of the overall Caucasian population, about 40% have two methionine-containing alleles, 10% have two valine-containing alleles, and the other 50% are heterozygous at this position. Only a single vCJD patient tested was found to be heterozygous; most of those affected had two copies of the methionine-containing form. Additionally, for unknown reasons, those affected are generally under the age of 40. It is not yet known whether those unaffected are actually immune or only have a longer incubation period until symptoms appear.

Inflammatory demyelinating diseases (IDDs), sometimes called Idiopathic (IIDDs) because the unknown etiology of some of them, and sometimes known as borderline forms of multiple sclerosis, is a collection of multiple sclerosis variants, sometimes considered different diseases, but considered by others to form a spectrum differing only in terms of chronicity, severity, and clinical course.

Multiple Sclerosis for some people is a syndrome more than a single disease. It can be considered among the acquired demyelinating syndromes with a multiphasic instead of monophasic behaviour. Multiple sclerosis also has a prodromal stage in which an unknown underlying condition, able to damage the brain, is present, but no lesion has still developed.

Currently PTCL is treated similarly to B-cell lymphomas. However, in recent years, scientists have developed techniques to better recognize the different types of lymphomas, such as PTCL. It is now understood that PTCL behaves differently from B-cell lymphomas and therapies are being developed that specifically target these types of lymphoma. Currently, however, there are no therapies approved by the US Food and Drug Administration (FDA) specifically for PTCL. Anthracycline-containing chemotherapy regimens are commonly offered as the initial therapy. Some patients may receive a stem cell transplant. Novel approaches to the treatment of PTCL in the relapsed or refractory setting are under investigation.

Pralatrexate is one compound currently under investigations for the treatment of PTCL. For information please consult the US clinical trials database (http://www.clinicaltrials.gov).