Signs and symptoms
 | This section is empty. You can help by adding to it. (December 2021) |
| Hypokalemic sensory overstimulation | |
|---|---|
| Specialty | Neurology |
| Symptoms | Sensory overload, relative resistance to lidocaine local anesthesia |
| Causes | Disorders of ion channels |
| Differential diagnosis | Attention deficit hyperactivity disorder, pulpitis |
| Treatment | Potassium gluconate, avoiding high carbohydrate meals |
Hypokalemic sensory overstimulation is a neurological disorder characterized by a subjective experience of sensory overload and a relative resistance to lidocaine local anesthesia. The sensory overload is treatable with oral potassium gluconate. Individuals with this condition are sometimes diagnosed as having attention deficit hyperactivity disorder (ADHD), raising the possibility that a subtype of ADHD has a cause that can be understood mechanistically and treated in a novel way.
It is not to be confused with hot tooth syndrome.
| | This section is empty. You can help by adding to it. (December 2021) |
Hypokalemic sensory overstimulation is a term coined by MM Segal and colleagues to describe a syndrome of sensory overstimulation, ineffectiveness of the local anesthetic lidocaine, and in females, premenstrual syndrome (PMS). [1] This initial report was followed by discussion in a second article of tens of families with apparent autosomal dominant inheritance of this condition. [2] The similarities were described clinically to ADHD and mechanistically and therapeutically to disorders of ion channels, in particular to the muscle disorder hypokalemic periodic paralysis. Some females with premenstrual syndrome may have the same autosomal dominant disorder underlying their symptoms. [2]
A test for lidocaine ineffectiveness was briefly described in the 2014 paper, [2] but the controlled trial has not yet been completed. [3]
The use of oral potassium and avoiding high carbohydrate meals can help treat it according to recent tests, following the same approach that is standard for the muscle disease hypokalemic periodic paralysis. [4] [5]
Since this condition includes ineffectiveness of the sodium-channel blocker lidocaine, the amide-type local anesthetic used in dental care, articaine, was tested and found to be effective in one member of the family. [1] No data about other local anesthetics effective in these individuals for non-dental procedures has yet been published.
Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterised by executive dysfunction occasioning symptoms of inattention, hyperactivity, impulsivity and emotional dysregulation that are excessive and pervasive, impairing in multiple contexts, and developmentally-inappropriate.
Local anesthesia is any technique to induce the absence of sensation in a specific part of the body, generally for the aim of inducing local analgesia, i.e. local insensitivity to pain, although other local senses may be affected as well. It allows patients to undergo surgical and dental procedures with reduced pain and distress. In many situations, such as cesarean section, it is safer and therefore superior to general anesthesia.
Restless legs syndrome, (also known as restless leg syndrome (RLS) and Willis–Ekbom disease(WED), is a neurological disorder, usually chronic, that causes an overwhelming urge to move one's legs. There is often an unpleasant feeling in the legs that improves temporarily by moving them. This feeling is often described as aching, tingling, or crawling in nature. Occasionally, arms may also be affected. The feelings generally happen when at rest and therefore can make it hard to sleep. Sleep disruption may leave people with RLS sleepy during the day, with low energy, and irritable or depressed. Additionally, many have limb twitching during sleep, a condition known as periodic limb movement disorder. RLS is not the same as habitual foot-tapping or leg-rocking.
Developmental disorders comprise a group of psychiatric conditions originating in childhood that involve serious impairment in different areas. There are several ways of using this term. The most narrow concept is used in the category "Specific Disorders of Psychological Development" in the ICD-10. These disorders comprise developmental language disorder, learning disorders, developmental coordination disorders, and autism spectrum disorders (ASD). In broader definitions, attention deficit hyperactivity disorder (ADHD) is included, and the term used is neurodevelopmental disorders. Yet others include antisocial behavior and schizophrenia that begins in childhood and continues through life. However, these two latter conditions are not as stable as the other developmental disorders, and there is not the same evidence of a shared genetic liability.
Conversion disorder (CD), or functional neurologic symptom disorder (FNsD), is a functional disorder that causes abnormal sensory experiences and movement problems during periods of high psychological stress. Individuals with CD present with highly distressing neurological symptoms such as numbness, blindness, paralysis, or convulsions, which are not consistent with a well-established organic cause and can be traced back to a psychological trigger.
Fasoracetam is an experimental drug of the racetam group which was never marketed. It is a putative nootropic that failed to show sufficient efficacy in clinical trials for vascular dementia. The drug was also subsequently repurposed for treatment of a variety of other conditions, such as attention deficit hyperactivity disorder (ADHD), but effectiveness for ADHD was disappointing and development of fasoracetam for most other conditions has been discontinued as well. In any case, it remains under development for treatment of DiGeorge syndrome.
Hyperkalemic periodic paralysis is an inherited autosomal dominant disorder that affects sodium channels in muscle cells and the ability to regulate potassium levels in the blood. It is characterized by muscle hyperexcitability or weakness which, exacerbated by potassium, heat or cold, can lead to uncontrolled shaking followed by paralysis. Onset usually occurs in early childhood, but it still occurs with adults.
Andersen–Tawil syndrome, also called Andersen syndrome and long QT syndrome 7, is a rare genetic disorder affecting several parts of the body. The three predominant features of Andersen–Tawil syndrome include disturbances of the electrical function of the heart characterised by an abnormality seen on an electrocardiogram and a tendency to abnormal heart rhythms, physical characteristics including low-set ears and a small lower jaw, and intermittent periods of muscle weakness known as hypokalaemic periodic paralysis.
Sensory overload occurs when one or more of the body's senses experiences over-stimulation from the environment.
Cognitive disengagement syndrome (CDS) is a syndrome characterized by developmentally-inappropriate, impairing and persistent levels of decoupled attentional processing from the ongoing external context and resultant hypoactivity. Symptoms often manifest in difficulties with staring, mind blanking, withdrawal, mental confusion and maladaptive mind wandering alongside delayed, sedentary or slow motor movements. To scientists in the field, it has reached the threshold of evidence and recognition as a distinct syndrome.
Periodic paralysis is a group of rare genetic diseases that lead to weakness or paralysis from common triggers such as cold, heat, high carbohydrate meals, not eating, stress or excitement and physical activity of any kind. The underlying mechanism of these diseases are malfunctions in the ion channels in skeletal muscle cell membranes that allow electrically charged ions to leak in or out of the muscle cell, causing the cell to depolarize and become unable to move.
Hypokalemic periodic paralysis (hypoKPP), also known as familial hypokalemic periodic paralysis (FHPP), is a rare, autosomal dominant channelopathy characterized by muscle weakness or paralysis when there is a fall in potassium levels in the blood (hypokalemia). In individuals with this mutation, attacks sometimes begin in adolescence and most commonly occur with individual triggers such as rest after strenuous exercise, high carbohydrate meals, meals with high sodium content, sudden changes in temperature, and even excitement, noise, flashing lights, cold temperatures and stress. Weakness may be mild and limited to certain muscle groups, or more severe full-body paralysis. During an attack, reflexes may be decreased or absent. Attacks may last for a few hours or persist for several days. Recovery is usually sudden when it occurs, due to release of potassium from swollen muscles as they recover. Some patients may fall into an abortive attack or develop chronic muscle weakness later in life.
Articaine is a dental amide-type local anesthetic. It is the most widely used local anesthetic in a number of European countries and is available in many countries. It is the only local anaesthetic to contain a thiophene ring, meaning it can be described as 'thiophenic'; this conveys lipid solubility.
Tourette syndrome is an inherited neurodevelopmental disorder that begins in childhood or adolescence, characterized by the presence of motor and phonic tics. The management of Tourette syndrome has the goal of managing symptoms to achieve optimum functioning, rather than eliminating symptoms; not all persons with Tourette's require treatment, and there is no cure or universally effective medication. Explanation and reassurance alone are often sufficient treatment; education is an important part of any treatment plan.
Sodium channel protein type 4 subunit alpha is a protein that in humans is encoded by the SCN4A gene.
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, tauopathies, and altered levels of consciousness. There are many recognized neurological disorders, some are relatively common, but many are rare.
In psychology and neuroscience, executive dysfunction, or executive function deficit, is a disruption to the efficacy of the executive functions, which is a group of cognitive processes that regulate, control, and manage other cognitive processes. Executive dysfunction can refer to both neurocognitive deficits and behavioural symptoms. It is implicated in numerous psychopathologies and mental disorders, as well as short-term and long-term changes in non-clinical executive control. Executive dysfunction is the mechanism underlying ADHD paralysis, and in a broader context, it can encompass other cognitive difficulties like planning, organizing, initiating tasks and regulating emotions. It is a core characteristic of ADHD and can elucidate numerous other recognized symptoms.
Vestibulocerebellar syndrome, also known as vestibulocerebellar ataxia, is a progressive neurological disorder that causes a variety of medical problems. Initially symptoms present as periodic attacks of abnormal eye movements but may intensify to longer-lasting motor incapacity. The disorder has been localized to the vestibulocerebellum, specifically the flocculonodular lobe. Symptoms of vestibulocerebellar syndrome may appear in early childhood but the full onset of neurological symptoms including nystagmus, ataxia, and tinnitus does not occur until early adulthood. To date, vestibulocerebellar syndrome has only been identified in three families but has affected multiple generations within them. Based on the familial pedigrees it has been characterized as an autosomal dominant disorder, although the exact genetic locus has not been identified. It has been found to be genetically distinct from other seemingly similar forms of neurological syndromes such as episodic ataxia types 1 and 2. Due to its rarity, however, little is known about specific details of the pathology or long-term treatment options. There is currently no cure for vestibulocerebellar syndrome, although some drug therapies have been effective in alleviating particular symptoms of the disorder.
Thyrotoxic periodic paralysis (TPP) is a rare condition featuring attacks of muscle weakness in the presence of hyperthyroidism. Hypokalemia is usually present during attacks. The condition may be life-threatening if weakness of the breathing muscles leads to respiratory failure, or if the low potassium levels lead to abnormal heart rhythms. If untreated, it is typically recurrent in nature.
Louis Ptáček is an American neurologist and professor who contributed greatly to the field of genetics and neuroscience. He was also an HHMI investigator from 1997 to 2018. His chief areas of research include the understanding of inherited Mendelian disorders and circadian rhythm genes. Currently, Ptáček is a neurology professor and a director of the Division of Neurogenetics in University of California, San Francisco, School of Medicine. His current investigations primarily focus on extensive clinical studies in families with hereditary disorders, which include identifying and characterizing the genes responsible for neurological variations.
