Symptoms are very similar to those found in benign fasciculation syndrome and include:

- Fasciculations (Primary Symptom)

- Muscle cramping (Primary Symptom)

- Muscle pain

- Muscle Stiffness

- Generalized fatigue

- Anxiety

- Exercise intolerance

- Globus sensations

- Paraesthesias.

- Hyperreflexia

The procedure of diagnosis for Cramp Fasciculation Syndrome (CFS) is closely aligned with the diagnosis procedure for benign fasciculation syndrome (BFS). The differentiation between a diagnosis of BFS versus CFS is usually more severe and prominent pain, cramps and stiffness associated with CFS.

May–White syndrome is a rare familial progressive myoclonus epilepsy with lipomas, deafness, and ataxia. This syndrome is probably a familial form of mitochondrial encephalomyopathy.

Familial Isolated Vitamin E Deficiency also known as Ataxia With Vitamin E Deficiency is a rare autosomal recessive neurodegenerative disease. Symptoms are similar to those of Friedreich ataxia.

Hemiplegic migraine or Hemiplegic migraine headache is a rare and serious subtype of classical migraine that typically includes weakness of half the body which can last for hours, days or weeks. It can be accompanied by other symptoms, such as ataxia, coma and paralysis.

The ICHD classification and diagnosis of migraine distinguish 6 subtypes of hemiplegic migraine. FHM can be loosely divided into two categories: with and without cerebellar signs. Cerebellar signs refer to ataxia, sometimes episodic and other times progressive, that can accompany FHM1 mutations and is caused by degeneration of the cerebellum. These cerebellar signs result in a phenotypic overlap between FHM and both episodic ataxia and spinocerebellar ataxia. This is unsurprising as subtypes of these disorders (FHM1, EA2 and SCA6) are allelic, i.e., they result from mutations in the same gene. The other forms of FHM seem to be distinguishable only on the basis of their genetic cause.

Episodes are relatively short-lived, lasting anywhere from 5–30 minutes, and in most cases disappear completely after cessation of the physical exercise. Most patients will experience 1 to 5 episodes per month, but some can have attacks daily. The muscles most often affected are usually in the legs and feet (75% of reported cases), but the upper body muscles such as the arms, face, neck, and trunk have also been observed to be affected during the episodes of dystonia. Age of onset is usually sometime in childhood, but can range from 1–30 years old. In one study it was found that the mean age of onset was around 8 years. Similarly in the study, the legs were the most common affected part of the body and the attacks were reported as stiffening and cramps by those affected.During an episode of PED patients find walking nearly impossible.Cerebral spinal fluid (CSF) analysis showed a two-fold increase of homovanillic acid and 5-hydroxyindoleacetic acid immediately following exercise compared to normal levels. This indicated that increased dopaminergic transmission could contribute to PED and other paroxysmal dyskinesias. Neurological examinations, EEG, and brain imaging are all normal in PED patients.

Familial Isolated Vitamin E Deficiency is caused by mutations in the gene for a-tocopherol transfer protein.

Early signs often include weakness of tongue and mouth muscles, fasciculations, and gradually increasing weakness of limb muscles with muscle wasting. Neuromuscular management is supportive, and the disease progresses very slowly, but can eventually lead to extreme disability. Further signs and symptoms include:

The classification of this syndrome is difficult. Three conditions are known to be caused by mutations in the" CYLD" gene: Brooke-Spiegler syndrome, multiple familial trichoepithelioma, and familial cylindromatosis. Clinically, these are distinct, but appear to arise from mutations in the same gene.

Types include:

Individuals with SBMA have muscle cramps and progressive weakness due to degeneration of motor neurons in the brain stem and spinal cord. Ages of onset and severity of manifestations in affected males vary from adolescence to old age, but most commonly develop in middle adult life. The syndrome has neuromuscular and endocrine manifestations.

Paroxysmal exercise-induced dystonia or PED is a rare neurological disorder characterized by sudden, transient, involuntary movements, often including repetitive twisting motions and painful posturing triggered by exercise or other physical exertion. PED is in the class of paroxysmal dyskinesia which are a group of rare movement disorders characterized by attacks of hyperkinesia with intact consciousness. The term paroxysmal indicates that the episodes are sudden and short lived and usually unpredicted, and return to normal is rapid. The number of reported cases of people with PED is very small leading to difficulty in studying and classifying this disease and most studies are limited to a very small number of test subjects.

Brooke-Spiegler syndrome is a condition where multiple skin tumors develop from skin structures. Tumors commonly occurring in this syndrome include spiradenomas, trichoepitheliomas, and cylindromas. The tumors are generally benign, but may become malignant. Affected individuals are also at increased risk of developing tumors in tissues other than skin – particularly benign or malignant tumors of the salivary glands.

Tumours in Brooke-Spiegler typically appear in early adulthood and are most often found on the head and neck. In severe cases, the tumors may affect vision or hearing. They can be disfiguring and may contribute to depression or other psychological problems. For unclear reasons, females are often more severely affected than males.

Brooke-Spiegler is rare and its exact incidence is unknown.

It is inherited in an autosomal dominant fashion.

The familial amyloid neuropathies (or familial amyloidotic neuropathies, neuropathic heredofamilial amyloidosis, familial amyloid polyneuropathy) are a rare group of autosomal dominant diseases wherein the autonomic nervous system and/or other nerves are compromised by protein aggregation and/or amyloid fibril formation.

Most RMD symptoms are relatively passive and do not cause any pain. Many patients are often unaware that an episode is occurring or has occurred. The rhythmic movements may produce some bodily injury via falls or muscle strains, but this is not reported in all patients

. In unique cases, RMD sufferers hum or moan while asleep during an episode. Some patients describe the repetitive movements as relaxing and are only occasionally awakened by an RMD episode. Often, it is the sufferer’s partner or parent who first notes the symptoms. Additionally, it is often the partner or parent who led patients to seek medical attention.

Rhythmic Movement Disorder (or RMD) is a neurological disorder characterized by involuntary (however may sometimes be voluntary), repetitive movements of large muscle groups immediately before and during sleep often involving the head and neck. It was independently described first in 1905 by Zappert as jactatio capitis nocturna and by Cruchet as rhythmie du sommeil. The majority of RMD episodes occur during NREM sleep, although REM movements have been reported. RMD is often associated with other psychiatric conditions or mental retardation. The disorder often leads to bodily injury from unwanted movements. Because of these incessant muscle contractions, patients’ sleep patterns are often disrupted. It differs from Restless Legs Syndrome in that RMD involves involuntary muscle contractions before and during sleep while Restless Legs Syndrome is the urge to move before sleep. RMD occurs in both males and females, often during early childhood with symptoms diminishing with age. Many sufferers also have other sleep related disorders, like sleep apnea. The disorder can be differentially diagnosed into small subcategories, including sleep related bruxism, thumb sucking, hypnagonic foot tremor, and rhythmic sucking, to name a few. In order to be considered pathological, the ICSD-II requires that in the sleep-related rhythmic movements should “markedly interfere with normal sleep, cause significant impairment in daytime function, or result in self-inflicted bodily injury that requires medical treatment (or would result in injury if preventive measures were not used)”

Benign familial infantile epilepsy (BFIE), also known as benign familial infantile seizures (BFIS) or benign familial infantile convulsions (BFIC) is an epilepsy syndrome. Affected children, who have no other health or developmental problems, develop seizures during infancy. These seizures have focal origin within the brain but may then spread to become generalised seizures. The seizures may occur several times a day, often grouped in clusters over one to three days followed by a gap of one to three months. Treatment with anticonvulsant drugs is not necessary but they are often prescribed and are effective at controlling the seizures. This form of epilepsy resolves after one or two years, and appears to be completely benign. The EEG of these children, between seizures, is normal. The brain appears normal on MRI scan.

A family history of epilepsy in infancy distinguishes this syndrome from the non-familial classification (see benign infantile epilepsy), though the latter may be simply sporadic cases of the same genetic mutations. The condition is inherited with an autosomal dominant transmission. There are several genes responsible for this syndrome, on chromosomes 2, 16 and 19. It is generally described as idiopathic, meaning that no other neurological condition is associated with it or causes it. However, there are some forms that are linked to neurological conditions. One variant known as infantile convulsions and choreoathetosis (ICCA) forms an association between BFIE and paroxysmal kinesigenic choreoathetosis and has been linked to the PRRT2 gene on chromosome 16. An association with some forms of familial hemiplegic migraine (FHM) has also been found. Benign familial infantile epilepsy is not genetically related to benign familial neonatal epilepsy (BFNE), which occurs in neonates. However, a variation with seizure onset between two days and seven months called "benign familial neonatal–infantile seizures" (BFNIS) has been described, which is due to a mutation in the SCN2A gene.

Mauriac syndrome is a rare complication of diabetes mellitus type 1 characterized by extreme hepatomegaly due to glycogen deposition, along with growth failure and delayed puberty. It occurs in children and adolescents with type 1 diabetes as a result of abnormally high blood sugar levels and the symptoms tend to rectify with attainment of normal blood sugar levels. Abnormally high blood sugar levels are relatively common among patients with type I diabetes, but Mauriac syndrome is rare suggesting that a factor affecting glycogen metabolism in addition to the high level of blood sugar is necessary to cause the syndrome. A study of an adolescent boy with severe Mauriac syndrome found a mutation in PHKG2 which is the catalytic subunit of glycogen phosphorylase kinase (PhK). PhK is a large enzyme complex responsible for the activation of glycogen phosphorylase, the first enzyme in the pathway of glycogen metabolism. Expression of the mutant PHKG2 in a human liver cell line inhibited the enzyme activity of the PhK complex and increased glycogen levels. The mother of the boy with Mauriac syndrome possessed the mutant PHKG2, but did not have diabetes or a clinically detectable enlarged liver. The father of the boy had type 1 diabetes with abnormally high blood sugar levels and the size of his liver and his growth were normal. The study suggests that a mutant enzyme of glycogen metabolism in addition to an abnormally high blood glucose level is necessary to cause Mauriac syndrome.

Usually beginning in one or both hands, MMN is characterized by weakness, muscle atrophy, cramping, and often profuse fasciculations (muscle twitching). The symptoms are progressive over long periods, often in a stepwise fashion, but unlike ALS are often treatable.

Sensory nerves are usually unaffected.

Wrist drop and foot drop (leading to trips and falls) are common symptoms. Other effects can include gradual loss of finger extension, leading to a clawlike appearance. Cold & hot temperatures exacerbates MMN symptoms to such an extent, unlike other neuropathies, that it is being investigated as a diagnostic tool.

The aggregation of one precursor protein leads to peripheral neuropathy and/or autonomic nervous system dysfunction. These proteins include: transthyretin (ATTR, the most commonly implicated protein), apolipoprotein A1, and gelsolin.

Due to the rareness of the other types of familial neuropathies, transthyretin amyloidogenesis-associated polyneuropathy should probably be considered first.

"FAP-I" and "FAP-II" are associated with transthyretin. (Senile systemic amyloidosis [abbreviated "SSA"] is also associated with transthyretin aggregation.)

"FAP-III" is also known as "Iowa-type", and involves apolipoprotein A1.

"FAP-IV" is also known as "Finnish-type", and involves gelsolin.

Fibrinogen, apolipoprotein A1, and lysozyme are associated with a closely related condition, familial visceral amyloidosis.

If nasopharyngeal angiofibroma is suspected based on physical examination (a smooth vascular submucosal mass in the posterior nasal cavity of an adolescent male), imaging studies such as CT or MRI should be performed. Biopsy should be avoided as to avoid extensive bleeding since the tumor is composed of blood vessels without a muscular coat.

Antral sign or Holman-Miller sign (forward bowing of posterior wall of maxilla) is pathognomic of angiofibroma.

DSA (digital subtraction angiography) of carotid artery to see the extension of tumors and feeding vessels

Nasopharyngeal angiofibroma (also called juvenile nasopharyngeal angiofibroma) is a histologically benign but locally aggressive vascular tumor that grows in the back of the nasal cavity. It most commonly affects adolescent males. Patients with nasopharyngeal angiofibroma usually present with one-sided nasal obstruction and recurrent bleeding.

Multifocal motor neuropathy (MMN) is a progressively worsening condition where muscles in the extremities gradually weaken. The disorder, a pure motor neuropathy syndrome, is sometimes mistaken for amyotrophic lateral sclerosis (ALS) because of the similarity in the clinical picture, especially if muscle fasciculations are present. MMN is thought to be autoimmune. It was first described in the mid-1980s.

Unlike ALS which affects both upper and lower motor nerves, MMN involves only lower motor nerves. Nevertheless, definitive diagnosis is often difficult, and many MMN patients labor for months or years under an ALS diagnosis before finally getting a determination of MMN.

MMN usually involves very little pain however muscle cramps, spasms and twitches can cause pain for some sufferers. MMN is not fatal, and does not diminish life expectation. Many patients, once undergoing treatment, only experience mild symptoms over prolonged periods, though the condition remains slowly progressive. MMN can however, lead to significant disability, with loss of function in hands affecting ability to work and perform everyday tasks, and "foot drop" leading to inability to stand and walk; some patients end up using aids like canes, splints and walkers.

A cyst of Montgomery is a benign breast mass, usually found in adolescent girls. Typically, it resolves spontaneously by itself.

Onset of PLS usually occurs spontaneously after age 50 and progresses gradually over a number of years, or even decades. The disorder usually begins in the legs, but it may start in the tongue or the hands. Symptoms may include difficulty with balance, weakness and stiffness in the legs, and clumsiness. Other common symptoms are spasticity (involuntary muscle contraction due to the stretching of muscle, which depends on the velocity of the stretch) in the hands, feet, or legs, foot dragging, and speech and swallowing problems due to involvement of the facial muscles. Breathing may also become compromised in the later stages of the disease, causing those patients who develop ventilatory failure to require noninvasive ventilatory support. Hyperreflexia is another key feature of PLS as seen in patients presenting with the Babinski's sign. Some people present with emotional lability and bladder urgency, and occasionally people with PLS experience mild cognitive changes detectable on neuropsychological testing, particularly on measures of executive function.

PLS is not considered hereditary when onset is in adulthood; however, juvenile primary lateral sclerosis (JPLS) has been linked to a mutation in the ALS2 gene which encodes the cell-signalling protein alsin.

The issue of whether PLS exists as a different entity from ALS is not clear, as some patients initially diagnosed as having PLS ultimately develop lower motor neuron signs.

There are no specific tests for the diagnosis of PLS. Therefore, the diagnosis occurs as the result of eliminating other possible causes of the symptoms and by an extended observation period.