Focal paroxysmal kinesigenic choreoathetosis

Movement Disorders in Multiple Sclerosis: An Update

Background:

Multiple sclerosis (MS), a subset of chronic primary inflammatory demyelinating disorders of the central nervous system, is closely associated with various movement disorders. These disorders may be due to MS pathophysiology or be coincidental. This review describes the full spectrum of movement disorders in MS with their possible mechanistic pathways and therapeutic modalities.

Methods:

The authors conducted a narrative literature review by searching for ‘multiple sclerosis’ and the specific movement disorder on PubMed until October 2021. Relevant articles were screened, selected, and included in the review according to groups of movement disorders.

Results:

The most prevalent movement disorders described in MS include restless leg syndrome, tremor, ataxia, parkinsonism, paroxysmal dyskinesias, chorea and ballism, facial myokymia, including hemifacial spasm and spastic paretic hemifacial contracture, tics, and tourettism. The anatomical basis of some of these disorders is poorly understood; however, the link between them and MS is supported by clinical and neuroimaging evidence. Treatment options are disorder-specific and often multidisciplinary, including pharmacological, surgical, and physical therapies.

Discussion:

Movements disorders in MS involve multiple pathophysiological processes and anatomical pathways. Since these disorders can be the presenting symptoms, they may aid in early diagnosis and managing the patient, including monitoring disease progression. Treatment of these disorders is a challenge. Further work needs to be done to understand the prevalence and the pathophysiological mechanisms responsible for movement disorders in MS.

Exercise-induced seizures and lateral asymmetry in patients with temporal lobe epilepsy

Objective

The objective of this case report is to better characterize the clinical features and potential pathophysiological mechanisms of exercise-induced seizures.

Methods

We report a case series of ten patients from a tertiary epilepsy center, where a clear history was obtained of physical exercise as a reproducible trigger for seizures.

Results

The precipitating type of exercise was quite specific for each patient, and various forms of exercise are described including running, swimming, playing netball, dancing, cycling, weight lifting, and martial arts. The level of physical exertion also correlated with the likelihood of seizure occurrence. All ten patients had temporal lobe abnormalities, with nine of the ten patients having isolated temporal lobe epilepsies, as supported by seizure semiology, EEG recordings, and both structural and functional imaging. Nine of the ten patients had seizures that were lateralized to the left (dominant) hemisphere. Five patients underwent surgical resection, with no successful long-term postoperative outcomes.

Conclusions

Exercise may be an underrecognized form of reflex epilepsy, which tended to be refractory to both medical and surgical interventions in our patients. Almost all patients in our cohort had seizures localizing to the left temporal lobe. We discuss potential mechanisms by which exercise may precipitate seizures, and its relevance regarding our understanding of temporal lobe epilepsy and lateralization of seizures. Recognition of, as well as advice regarding avoidance of, known triggers forms an important part of management of these patients.

Paroxysmal kinesigenic segmental myoclonus due to a spinal cord glioma

We report an 18-year-old man with paroxysmal jerking movements of the left arm since age 7 years. These were invariably precipitated by startle or sudden movements. He was subsequently diagnosed with a cervical cord anaplastic astrocytoma on MRI. We could not identify previous reports of paroxysmal myoclonus secondary to a spinal cord neoplasm. We have coined the term Paroxysmal Kinesigenic Segmental Myoclonus to describe this entity.

Diagnosis and management of acute movement disorders

Most movement disorders, reflecting degenerative disorders, develop in a slowly progressive fashion. Some movement disorders, however, manifest with an acute onset. We wish to give an overview of the management and therapy of those acute-onset movement disorders.Drug-induced movement disorders are mainly caused by dopamine-receptor blockers (DRB) as used as antipsychotics (neuroleptics) and antiemetics. Acute dystonic reactions usually occur within the first four days of treatment. Typically, cranial pharyngeal and cervical muscles are affected. Anticholinergics produce a prompt relief. Akathisia is characterized by an often exceedingly bothersome feeling of restlessness and the inability to remain still. It is a common side effect of DRB and occurs within few days after their initiation. It subsides when DRB are ceased. Neuroleptic Malignant Syndrome is a rare, but life-threatening adverse reaction to DRB which may occur at any time during DRB application. It is characterised by hyperthermia, rigidity, reduced consciousness and autonomic failure. Therapeutically immediate DRB withdrawal is crucial. Additional dantrolene or bromocriptine application together with symptomatic treatment may be necessary. Paroxysmal dyskinesias are childhood onset disorders characterised by dystonic postures, chorea, athetosis and ballism occurring at irregular intervals. In Paroxysmal Kinesigenic Dyskinesia they are triggered by rapid movements, startle reactions or hyperventilation. They last up to 5 minutes, occur up to 100 times per day and are highly sensitive to anticonvulsants. In Paroxysmal Non-Kinesiogenic Dyskinesia they cannot be triggered, occur less frequently and last longer. Other paroxysmal dyskinesias include hypnogenic paroxysmal dyskinesias, paroxysmal exertional dyskinesia, infantile paroxysmal dystonias, Sandifer's syndrome and symptomatic paroxysmal dyskinesias. In Hereditary Episodic Ataxia Type 1 attacks of ataxia last for up to two minutes, may be accompanied by dysarthria and dystonia and usually respond to phenytoin. In Type 2 they can last for several hours, may be accompanied by vertigo, headache and malaise and usually respond to acetazolamide. Symptomatic episodic ataxias can occur in a number of metabolic disorders, but also in multiple sclerosis and Behcet's disease.

Childhood paroxysmal kinesigenic dyskinesia: report of seven cases with onset at an early age

We report on seven children who developed abnormal involuntary movements as early as 1.5 years after unremarkable term births. The paroxysmal episodes of abnormal movements were typically precipitated by sudden, voluntary movements, or a startle. The clinical features in each case were consistent with the diagnosis of paroxysmal kinesigenic dyskinesia (PKD). The episodes of abnormal movements are described. EEG was obtained in all cases, and video/electroencephalography (VEEG) monitoring was performed to exclude the possibility of epilepsy in six patients. VEEG studies revealed multiple events consistent with PKD; no ictal epileptiform discharges were recorded. The apparent benign nature of the disorder, as well as treatment options with antiepileptic drugs, was discussed with the parents, and most chose no pharmacologic treatment. We discuss clinical characteristics of PKD, treatment with anticonvulsant therapy, and recent insights into its possible pathophysiology.

Paroxysmal kinesigenic dyskinesias

The paroxysmal dyskinesias (PxDs) are involuntary, intermittent movement disorders manifested by dystonia, chorea, athetosis, ballismus or any combination of these hyperkinetic disorders. Paroxysmal kinesigenic dyskinesia (PKD), one of the four main types of PxD, involves sudden attacks of dyskinesias induced by voluntary movements. PKD most commonly occurs sporadically or as an autosomal-dominant familial trait with variable penetrance. Many causes of secondary PKD are being recognized. The exact pathophysiology of the PxDs awaits further elucidation, although basal ganglia dysfunction appears to play a major role. Although the precise gene remains unknown, genetic linkage studies have isolated loci on chromosome 16, which colocalizes with the locus for familial infantile convulsions and paroxysmal choreoathetosis in some studies. The episodic nature of PKD and its relationship with other episodic diseases, such as epilepsy, migraine, and episodic ataxia, suggests channelopathy as a possible underlying etiology. PKD may remit spontaneously, but it also responds well to anticonvulsants as well as some other agents.

Secondary paroxysmal dyskinesias

Paroxysmal dyskinesias (PxDs) are involuntary, episodic movements that include paroxysmal kinesigenic (PKD), paroxysmal nonkinesigenic (PNKD), and paroxysmal hypnogenic (PHD) varieties. Although most PxDs are primary (idiopathic or genetic), we found 17 of our 76 patients with PxD (22%) to have an identifiable cause for their PxD (10 men; mean age, 41.4 years). Causes included peripheral trauma (in three patients), vascular lesions (in four), central trauma (in four), kernicterus (in two), multiple sclerosis (in one), cytomegalovirus encephalitis (in one), meningovascular syphilis (in one), and migraine (in one). The latency from insult to symptom onset ranged from days (trauma) to 18 years (kernicterus), with a mean of 3 years. Nine patients had PNKD, two had PKD, five had mixed PKD/PNKD, and one had PHD. Hemidystonia was the most common expression of the paroxysmal movement disorder, present in 11 patients. Both of the patients with PKD had symptom durations of <5 minutes. Symptom duration ranged from 10 seconds to 15 days for PNKD and from 5 minutes to 45 minutes for mixed PKD/PNKD. There were no uniformly effective therapies, but anticonvulsant drugs, clonazepam, and botulinum toxin injections were the most beneficial. Awareness of the variable phenomenology and the spectrum of causes associated with secondary PxD will allow for more timely diagnosis and early intervention.

Paroxysmal kinesigenic choreoathetosis in Singapore and its relationship to epilepsy

OBJECTIVES

To study the clinical characteristics of paroxysmal kinesigenic choreoathetosis (PKC) in our local population and its relationship to epilepsy.

METHODS

We reviewed retrospectively 15 patients who were managed by neurologists in our department from 1982 to 1996. The literature was also reviewed to study the association between PKC and epilepsy.

RESULTS

In our study, all the cases were idiopathic. The male to female ratio was 14:1 with all major races represented. Sixty percent of our patients suffered dystonic posturing rather than chorea, during the attacks. Twenty-one percent had a family history of a similar disorder which appeared to be of autosomal dominant inheritance. The sporadic form (79%) predominated in Singapore. One had a history of febrile fits while two had a history of epilepsy. We reviewed the available literature and found five other patients with idiopathic PKC also suffering from epilepsy. Of the 83 patients reviewed, 8% had epilepsy. This further strengthens the relationship between the two conditions. All our patients responded well to phenytoin at doses between 100 and 400 mg/day.

CONCLUSION

PKC affected all three major races in our population with a high male to female ratio of 14:1. Seventy-nine percent of our cases were sporadic and 60% suffered dystonic posturing during attacks. Of the cases reviewed, 8% of patients with idiopathic PKC also had epilepsy.

Paroxysmal dyskinesias: clinical features and classification

We studied 46 patients with paroxysmal dyskinesia and classified them according to phenomenology, duration of attacks, and etiology. There were 13 patients, 7 females, who had paroxysmal kinesigenic dyskinesia (PKD), 10 with attacks lasting 5 minutes or less (short lasting) and 3 with attacks lasting longer than 5 minutes (long lasting). Twenty-six patients, 18 females, had paroxysmal nonkinesigenic dyskinesia (PNKD), 9 with short-lasting and 17 with long-lasting PNKD. Five patients, 3 females, had paroxysmal exertion-induced dyskinesia (PED), 3 with short-lasting PED and the other 2 with long-lasting PED. In addition, there was 1 patient with paroxysmal hypnogenic dyskinesia (PHD) and 1 with paroxysmal superior oblique myokymia. Only 2 patients, 1 with PKD and 1 with PHD, had family history of paroxysmal dyskinesias. No specific cause could be identified in 21 patients; in the other 23 patients the etiologies included the following: psychogenic (9 patients), cerebrovascular diseases (4), multiple sclerosis (2), encephalitis (2), cerebral trauma (2), peripheral trauma (2), migraine (1), and kernicterus (1). Nine of 10 (90%) patients with PKD improved with medications, mostly anticonvulsants, compared with only 7 of 19 (37%) with PNKD. This new classification, based chiefly on precipitating events, allowed appropriate categorization of the attacks in all our patients with paroxysmal dyskinesias.

Paroxysmal choreoathetosis: an epileptic or non-epileptic disorder?

The pathophysiology of paroxysmal kinesigenic choreoathetosis (PKC) is controversial. Some classify it as a non-epileptic movement disorder, others consider PKC as a form of reflex-epilepsy but postulate that the epileptogenic source is within basal ganglia rather than in the cortex. An extensive invasive longterm monitoring in a girl with PKC demonstrated a consistent ictal discharge arising focally from the supplementary sensory-motor cortex (SMC), with a concomitant discharge recorded from the ipsilateral caudate nucleus, without significant spread to other neocortical areas. An hypothesis is presented to explain how a focal discharge within the supplementary motor cortex, demonstrated for the first time to occur in a patient with PKC, might cause phenomenologies distinct from the habitual SMC seizures and strongly suggesting a basal ganglia semeiology.

Paroxysmal kinesigenic choreoathetosis as presenting symptom of multiple sclerosis

Images

Autosomal dominant episodic ataxia: a heterogeneous syndrome

We describe six kindreds with autosomal dominant episodic ataxia, apparently representing three distinct syndromes. Four kindreds were characterized by episodic ataxia and response to acetazolamide, and in three, interictal nystagmus. One kindred was characterized by paroxysmal ataxia and in one member, paroxysmal choreoathetosis. The last kindred had brief attacks of ataxia and interictal neuromyotonia. The age of onset and severity of the disorder varied within each kindred. These kindreds illustrate the heterogeneity of episodic ataxia as well as the variable expressivity within each kindred.

Familial paroxysmal dystonia induced by exercise

A mother and daughter are described with paroxysmal dystonia induced by exercise. As has been reported in one previous family, the attacks were provoked in the lower limbs by prolonged exertion but not by sudden movements. It was also found that involuntary movements could be induced focally in any limb either by local exercise or by sensory stimulation restricted to that limb.