Sensory-based motor disorder shows motor output that is disorganized as a result of incorrect processing of sensory information affecting postural control challenges, resulting in postural disorder, or developmental coordination disorder.

The SBMD subtypes are:

1. Dyspraxia

2. Postural disorder

Symptoms may vary according to the disorder's type and subtype present. SPD can affect one sense or multiple senses. While many people can present one or two symptoms, sensory processing disorder has to have a clear functional impact on the person's life.

Sensory dysfunction disorder is a reported neurological disorder of information processing, characterized by difficulty in understanding and responding appropriately to sensory inputs. Sensory dysfunction disorder is not recognized by the American Medical Association. "Sensory processing (SP) difficulties have been reported in as many as 95% of children with autism, however, empirical research examining the existence of specific patterns of SP difficulties within this population is scarce."

The brain receives messages from the body's sensory systems, which informs the brain of what is going on around and to a person's body. If one or more of these systems become overstimulated, it may result in what is known as Sensory Dysfunction Disorder. An example of a response to overstimulation is expressed by A. Jean Ayres, in "Sensory Integration and the Child: Understanding Hidden Sensory Challenges". She writes, "When the flow of sensations is disorganized, life can be like a rush-hour traffic jam” (p. 289). The following sensory systems are broken down into individual categories to better understand the impact a sensitivity can have on an individual.

The tactile system is the sense of touch. Someone with Sensory Dysfunction Disorder may have symptoms of not being able to process any form of physical connection. Conversely, a person may need to have some sort of physical connection to soothe an anxiety he or she is experiencing.

Auditory processing disorder (APD), also known as central auditory processing disorder (CAPD), is an umbrella term for a variety of disorders that affect the way the brain processes auditory information. Individuals with APD usually have normal structure and function of the outer, middle and inner ear (peripheral hearing). However, they cannot process the information they hear in the same way as others do, which leads to difficulties in recognizing and interpreting sounds, especially the sounds composing speech. It is thought that these difficulties arise from dysfunction in the central nervous system.

The American Academy of Audiology notes that APD is diagnosed by difficulties in one or more auditory processes known to reflect the function of the central auditory nervous system.

APD can affect both children and adults, although the actual prevalence is currently unknown. It has been suggested that males are twice as likely to be affected by the disorder as females, but there are no good epidemiological studies.

Whole body movement and motor coordination issues mean that major developmental targets including walking, running, climbing and jumping can be affected. The difficulties vary from person to person and can include the following:

- Poor timing

- Poor balance (sometimes even falling over in mid-step). Tripping over one's own feet is also common.

- Difficulty combining movements into a controlled sequence.

- Difficulty remembering the next movement in a sequence.

- Problems with spatial awareness, or proprioception.

- Trouble picking up and holding onto simple objects such as pencils, owing to poor muscle tone or proprioception.

- Clumsiness to the point of knocking things over and bumping into people accidentally.

- Difficulty in determining left from right.

- Cross-laterality, ambidexterity, and a shift in the preferred hand are also common in people with developmental coordination disorder.

- Problems with chewing foods.

Fine-motor problems can cause difficulty with a wide variety of other tasks such as using a knife and fork, fastening buttons and shoelaces, cooking, brushing one's teeth, styling one's hair, shaving, applying cosmetics, opening jars and packets, locking and unlocking doors, and doing housework.

Difficulties with fine motor co-ordination lead to problems with handwriting, which may be due to either ideational or ideo-motor difficulties.

Problems associated with this area may include:

- Learning basic movement patterns.

- Developing a desired writing speed.

- Establishing the correct pencil grip

- The acquisition of graphemes – e.g. the letters of the Latin alphabet, as well as numbers.

PRS symptoms have common characteristics with many other psychiatric disorders. However, none of the present DSM diagnoses can account for the full scope of symptoms seen in PRS, and refusal to eat, weight loss, social withdrawal and school refusal can be considered as the main distinctive features. Any system may be involved, however some more commonly engaged than others.

Gastrointestinal:

- recurring pain

- nausea

- loss of appetite

Neurological:

- headache

- seizure

- motor dysfunction

- sensory dysfunction

- fatigue

- altered consciousness

Musculoskeletal:

- joint pains

- muscle weakness

CAPD can continue into adulthood. Cooper and Gates (1991) estimated the prevalence of adult APD to be 10 to 20%. Many people experience problems with learning and day-to-day tasks with difficulties over time. Adults with this disorder

- talk louder than necessary

- have trouble remembering a list or sequence

- often need words or sentences repeated

- have poor ability to memorize information learned by listening

- interpret words too literally

- need assistance hearing clearly in noisy environments

- rely on accommodation and modification strategies

- find or request a quiet work space away from others

- request written material when attending oral presentations

- ask for directions to be given one step at a time

Olfactory dysfunction can be quantitative and/or qualitative. Quantitative smell disorders refer to disorders in which there is complete or partial loss of olfaction. Anosmia, the complete loss of olfaction, and hyposmia, the partial loss of olfaction are the two disorders classified as quantitative because they can be measured. Qualitative smell disorders can’t be measured and refer to disorders in which there is alternation or distortion in the perception of smell. Qualitative disorders include parosmia (also called troposmia) and phantosmia. The term dysosmia refers to a qualitative olfaction disorder and include both parosmia and phantosmia. Olfactory dysfunction including anosmia, hyposmia, and dysosmia can be either bilateral or unilateral on either nostril. Anosmia only on the left nostril would be termed unilateral left anosmia while bilateral anosmia would be termed total anosmia.

Sensory processing sensitivity (SPS), a personality trait, a high measure of which defines a highly sensitive person (HSP), has been described as having hypersensitivity to external stimuli, a greater depth of cognitive processing, and high emotional reactivity. The terms SPS and HSP were coined in the mid-1990s by psychologists Elaine Aron and husband Arthur Aron, with SPS being measured by Aron's Highly Sensitive Person Scale (HSPS) questionnaire. Other researchers have applied various other terms to denote this responsiveness to stimuli that is evidenced in humans and other species.

According to the Arons and colleagues, people with high SPS comprise about 15–20% of the population and are thought to process sensory data more deeply due to the nature of their central nervous system. Although many researchers consistently related high SPS to negative outcomes, Aron and colleagues state that high SPS is a personality trait and not a disorder; other researchers have associated it with increased responsiveness to both positive and negative influences.

Dysosmia is a disorder described as any qualitative alteration or distortion of the perception of smell. Qualitative alterations differ from quantitative alterations, which include anosmia and hyposmia. Dysosmia can be classified as either parosmia (also called troposmia) or phantosmia. Parosmia refers to a distortion in the perception of an odorant. Odorants smell different from what one remembers. Phantosmia refers to the perception of an odor when there's no actual odorant present. The cause of dysosmia still remains a theory. It is typically considered a neurological disorder and clinical associations with the disorder have been made. Most cases are described as idiopathic and the main antecedents related to parosmia are URTIs, head trauma, and nasal and paranasal sinus disease. Dysosmia tends to go away on its own but there are options for treatment for patients that want immediate relief.

Pervasive refusal syndrome (PRS), now referred to as pervasive arousal withdrawal syndrome (PAWS), is a rare but serious child psychiatric disorder that was first described by Bryan Lask and colleagues in 1991. As of 2011, it is not included in the standard psychiatric classification systems. PRS is the name allotted to a disorder in which children have abandoned their involvement in all phases of their life. It's characterized by refusal to eat, drink, talk, walk or self-care, and a firm resistance to treatment. PRS is very rare and its cause is unclear, but its severity makes it life-threatening. The disorder usually begins with a 'virus', or the child having a 'pain', that results in the need for consulting a doctor or going to the hospital, even though no substantial cause can be found. PRS starts slowly, but the child then worsens quickly becoming reluctant or not capable to do anything for themselves. They originally refuse to accept others caring for them, or helping them eat, and are very depressed and distraught. It is not guaranteed that recovery will take place, and it is a lengthy and complex process, involving specialist medical care. Nevertheless, once the patient is healthy, relapse is very infrequent.

A family with a psychiatric history or environmental stress factors can also play a role. Hospitalization is almost always necessary and the recovery period is lengthy; typically 12.8 months. During the recovery period symptoms disappear in the opposite order they appear. About 67% of the cases show complete recovery.

PRS may be linked to learned helplessness, and so it can be important for the patient to be able to manage the rate of their recovery. Music therapy may help in this regard as it provides empowerment by giving the patient choice and control, while allowing for improvisation can result in a sense of affirmation and validation; all important for a successful recovery.

In 73 individual cases reviewed by Evers and Ellger, 57 patients heard tunes that were familiar, while 5 heard unfamiliar tunes. These tunes ranged from religious pieces to childhood favorites, and also included popular songs from the radio. Vocal and instrumental forms of classical music were also identified in some patients. Keshavan found that the consistent feature of musical hallucinations was that it represented a personal memory trace. Memory traces refer to anything that may seem familiar to the patient, which indicated why certain childhood or familiar songs were heard.

Witzelsucht (from the German "witzeln", meaning to joke or wisecrack, and "sucht", meaning addiction or yearning) is a set of rare neurological symptoms characterized by a tendency to make puns, or tell inappropriate jokes or pointless stories in socially inappropriate situations. A less common symptom is hypersexuality, the tendency to make sexual comments at inappropriate times or situations. Patients do not understand that their behavior is abnormal, therefore are nonresponsive to others' reactions. This disorder is most commonly seen in patients with frontal lobe damage, particularly right frontal lobe tumors or trauma. The disorder remains named in accordance with its reviewed definition by German neurologist Hermann Oppenheim; its first description as the less focused "Moria" ("stupidity"), by German neurologist Moritz Jastrowitz, was in 1888.

Due to similarity of symptoms of the disorder to the mannerisms of Batman's arch-rival Joker, it is sometimes known as 'The Joker Syndrome'

When balance is impaired, an individual has difficulty maintaining upright orientation. For example, an individual may not be able to walk without staggering, or may not even be able to stand. They may have falls or near-falls. The symptoms may be recurring or relatively constant. When symptoms exist, they may include:

- A sensation of dizziness or vertigo.

- Lightheadedness or feeling woozy.

- Problems reading and difficulty seeing.

- Disorientation.

Some individuals may also experience nausea and vomiting, diarrhea, faintness, changes in heart rate and blood pressure, fear, anxiety, or panic. Some reactions to the symptoms are fatigue, depression, and decreased concentration. The symptoms may appear and disappear over short time periods or may last for a longer period.

Cognitive dysfunction (disorientation) may occur with vestibular disorders. Cognitive deficits are not just spatial in nature, but also include non-spatial functions such as object recognition memory. Vestibular dysfunction has been shown to adversely affect processes of attention and increased demands of attention can worsen the postural sway associated with vestibular disorders. Recent MRI studies also show that humans with bilateral vestibular damage undergo atrophy of the hippocampus which correlates with their degree of impairment on spatial memory tasks.

Investigators have successfully narrowed down the major factors that are associated with musical hallucinations. Evers and Ellgers compiled a significant portion of musical hallucination articles, case studies etc. and were able to categorize five major etiologies:

- Hypoacusis

- Psychiatric disorders

- Focal brain lesion

- Epilepsy

- Intoxication

Individuals with exploding head syndrome hear or experience loud imagined noises as they are falling asleep or waking up, have a strong, often frightened emotional reaction to the sound, and do not report significant pain; around 10% of people also experience visual disturbances like perceiving visual static, lightning, or flashes of light. Some people may also experience heat, strange feelings in their torso, or a feeling of electrical tinglings that ascends to the head before the auditory hallucinations occur. With the heightened arousal, people experience distress, confusion, myoclonic jerks, tachycardia, sweating, and the sensation that felt as if they had stopped breathing and had to make a deliberate effort to breathe again.

The pattern of the auditory hallucinations is variable. Some people report having a total of two or four attacks followed by a prolonged or total remission, having attacks over the course of a few weeks or months before the attacks spontaneously disappear, or the attacks may even recur irregularly every few days, weeks, or months for much of a lifetime.

Some individuals believe that EHS episodes are not natural events, but are the effects of directed energy weapons which create an auditory effect. Thus, EHS has been worked into conspiracy theories, but there is no scientific evidence that EHS has non-natural origins.

Problems with balance can occur when there is a disruption in any of the vestibular, visual, or proprioceptive systems. Abnormalities in balance function may indicate a wide range of pathologies from causes like inner ear disorders, low blood pressure, brain tumors, and brain injury including stroke.

Many different terms are often used for dizziness, including lightheaded, floating, woozy, giddy, confused, helpless, or fuzzy. Vertigo, Disequilibrium and pre-syncope are the terms in use by most physicians and have more precise definitions.

Vertigo

Vertigo is the sensation of spinning or having the room spin about you. Most people find vertigo very disturbing and report associated nausea and vomiting.

Disequilibrium

Disequilibrium is the sensation of being off balance, and is most often characterized by frequent falls in a specific direction. This condition is not often associated with nausea or vomiting.

Presyncope

Pre-syncope is a feeling of lightheadedness or simply feeling faint. Syncope, by contrast, is actually fainting. A circulatory system deficiency, such as low blood pressure, can contribute to a feeling of dizziness when one suddenly stands up.

Problems in the skeletal or visual systems, such as arthritis or eye muscle imbalance, may also cause balance problems.

Transcortical sensory aphasia (TSA) is a kind of aphasia that involves damage to specific areas of the temporal lobe of the brain, resulting in symptoms such as poor auditory comprehension, relatively intact repetition, and fluent speech with semantic paraphasias present. TSA is a fluent aphasia similar to Wernicke's aphasia, with the exception of a strong ability to repeat words and phrases. The person may repeat questions rather than answer them ("echolalia").

In all of these ways, TSA is very similar to a more commonly known language disorder, receptive aphasia. However, transcortical sensory aphasia differs from receptive aphasia in that patients still have intact repetition and exhibit echolalia, or the compulsive repetition of words. Transcortical sensory aphasia cannot be diagnosed through brain imaging techniques such as functional magnetic resonance imaging (fMRI), as the results are often difficult to interpret. Therefore, clinicians rely on language assessments and observations to determine if a patient presents with the characteristics of TSA. Patients diagnosed with TSA have shown partial recovery of speech and comprehension after beginning speech therapy. Speech therapy methods for patients with any subtype of aphasia are based on the principles of learning and neuroplasticity. Clinical research on TSA is limited because it occurs so infrequently in patients with aphasia that it is very difficult to perform systematic studies.

TSA should not be confused with transcortical motor aphasia (TMA), which is characterized by nonfluent speech output, with good comprehension and repetition. Patients with TMA have impaired writing skills, difficulty speaking and difficulty maintaining a clear thought process. Furthermore, TMA is caused by lesions in cortical motor areas of the brain as well as lesions in the anterior portion of the basal ganglia, and can be seen in patients with expressive aphasia.

In both case studies, patients showed an altered sense of humor, mostly in regard to producing and appreciating humor. The right hemisphere is involved with processing speed and problem solving, which plays a role in humor processing. These patients have difficulty fully interpreting a joke's content, but can recognize the importance of the form of a joke. Patients with witzelsucht often find non sequiturs, slapstick humor, and puns funniest since these forms of humor do not require integration of content across sentences. In other words, the end of the joke is not dependent on the first part; one does not need to make a logical connection to understand humor. Patients show no change in understanding simple logic, and understand the importance of surprise in humor (hence why they choose slapstick humor instead of the “correct” punch line); however, once they have registered this surprise, they cannot connect the punch line to the body of the joke to fully appreciate the true humor behind the joke. Successful jokes require a juxtaposition of the sound and the meaning of words used to understand the punch line. However, patients with witzelsucht have difficulty connecting the two, resulting in an inability to appreciate humor.

Additionally, patients show no emotional reaction to humor, whether produced by themselves or others. This lack of responsiveness is due to dissociation between their cognitive and affective responses to humorous stimuli. That is, even when a patient understands that a joke is funny (based on quantitative brain activity), they do not respond with laughter, or even a smile. While they have grasped the cognitive basis of humor, they do not affectively respond. This also considered a cognitive component of empathy, affecting ability to take the perspective of others; hence why patients often do not respond to humor produced by other people.

Patients with TSA typically exhibit paraphasia; their speech is fluent but often error-prone. Their speech is often unintelligible as they tend to use the wrong words, e.g. tree instead of train or uses words in senseless and incorrect combinations.

Exploding head syndrome is classified as a parasomnia and a sleep-related dissociative disorder by the 2005 International Classification of Sleep Disorders and is an unusual type of auditory hallucination in that it occurs in people who are not fully awake.

Neurological disorders can be categorized according to the primary location affected, the primary type of dysfunction involved, or the primary type of cause. The broadest division is between central nervous system disorders and peripheral nervous system disorders. The Merck Manual lists brain, spinal cord and nerve disorders in the following overlapping categories:

- Brain:

- Brain damage according to cerebral lobe "(see also 'lower' brain areas such as basal ganglia, cerebellum, brainstem)":

- Frontal lobe damage

- Parietal lobe damage

- Temporal lobe damage

- Occipital lobe damage

- Brain dysfunction according to type:

- Aphasia (language)

- Dysgraphia (writing)

- Dysarthria (speech)

- Apraxia (patterns or sequences of movements)

- Agnosia (identifying things or people)

- Amnesia (memory)

- Spinal cord disorders (see spinal pathology, injury, inflammation)

- Peripheral neuropathy and other Peripheral nervous system disorders

- Cranial nerve disorder such as Trigeminal neuralgia

- Autonomic nervous system disorders such as dysautonomia, Multiple System Atrophy

- Seizure disorders such as epilepsy

- Movement disorders of the central and peripheral nervous system such as Parkinson's disease, Essential tremor, Amyotrophic lateral sclerosis, Tourette's Syndrome, Multiple Sclerosis and various types of Peripheral Neuropathy

- Sleep disorders such as Narcolepsy

- Migraines and other types of Headache such as Cluster Headache and Tension Headache

- Lower back and neck pain (see Back pain)

- Central neuropathy (see Neuropathic pain)

- Neuropsychiatric illnesses (diseases and/or disorders with psychiatric features associated with known nervous system injury, underdevelopment, biochemical, anatomical, or electrical malfunction, and/or disease pathology e.g. Attention deficit hyperactivity disorder, Autism, Tourette's syndrome and some cases of obsessive compulsive disorder as well as the neurobehavioral associated symptoms of degeneratives of the nervous system such as Parkinson's disease, essential tremor, Huntington's disease, Alzheimer's disease, multiple sclerosis and organic psychosis.)

Many of the diseases and disorders listed above have neurosurgical treatments available (e.g. Tourette's Syndrome, Parkinson's disease, Essential tremor and Obsessive compulsive disorder).

- Delirium and dementia such as Alzheimer's disease

- Dizziness and vertigo

- Stupor and coma

- Head injury

- Stroke (CVA, cerebrovascular attack)

- Tumors of the nervous system (e.g. cancer)

- Multiple sclerosis and other demyelinating diseases

- Infections of the brain or spinal cord (including meningitis)

- Prion diseases (a type of infectious agent)

- Complex regional pain syndrome (a chronic pain condition)

Neurological disorders in non-human animals are treated by veterinarians.

A neurological disorder is any disorder of the nervous system. Structural, biochemical or electrical abnormalities in the brain, spinal cord or other nerves can result in a range of symptoms. Examples of symptoms include paralysis, muscle weakness, poor coordination, loss of sensation, seizures, confusion, pain and altered levels of consciousness. There are many recognized neurological disorders, some relatively common, but many rare. They may be assessed by neurological examination, and studied and treated within the specialities of neurology and clinical neuropsychology.

Interventions for neurological disorders include preventative measures, lifestyle changes, physiotherapy or other therapy, neurorehabilitation, pain management, medication, or operations performed by neurosurgeons. The World Health Organization estimated in 2006 that neurological disorders and their sequelae (direct consequences) affect as many as one billion people worldwide, and identified health inequalities and social stigma/discrimination as major factors contributing to the associated disability and suffering.