Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0027066 (myoclonus)
 4,275 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Recently it has been discovered that defects in neuronal ion channels can result in seizure disorders. The tottering mouse is a genetic animal model carrying a mutation in the alpha1A calcium channel subunit that causes these mice to exhibit generalized petit mal-like epilepsy, cerebellar ataxia, and an intermittent movement disorder that has some characteristics similar to myoclonus or myoclonic epilepsy. We postulate that abnormal cerebellar Purkinje cell output to the deep cerebellar nuclei results in the intermittent movement disorder observed in these mice. The frequency and duration of seizure activity were measured in tottering mice before and 2 weeks after surgical or chemical lesioning of the cerebellum. Surgical lesions in the anterior cerebellar vermis of tottering mice produced significant reductions in seizure duration and frequency. Surgical lesioning of the posterior cerebellar vermis had no significant effect. Chemical lesions of the same cerebellar regions, using a locally applied neurotoxin, NMD-L-A, appear to produce effects similar to the surgical lesions. These data indicate that anterior vermal cerebellar output is important for production of the seizures associated with the intermittent movement disorder observed in tottering mice.
 ...
PMID:Investigation of the role of the cerebellum in the myoclonic-like movement disorder exhibited by tottering mice. 1075 73

Inborn errors of metabolism (IEM) are a group of genetic disorders characterized by dysfunction of an enzyme or other protein involved in cellular metabolism.(1) Most IEMs involve the nervous system (neuro-metabolic diseases or NMD). NMD often present with a complex clinical picture: psychomotor retardation and/or regression, pyramidal signs, ataxia, hypotonia and epilepsy and movement disorders.(1) Movement disorders are more frequently part of this complex picture than a predominant symptom, however in some instances the clinical picture may be summarized in an invalidating movement disorder.(2) On a phenomenology basis, one can distinguish eight main types of movement disorders: dystonia and athetosis, chorea, tremor with or without parkinsonism, ballismus, myoclonus, tics and stereotypies. Most of these abnormal involuntary movements generate from a dysfunction or a lesion in the basal ganglia, excepting myoclonus, the origin of which can vary (cortical, brainstem, basal ganglia, spinal and even peripheral nervous system).(3) Classically the most frequently observed movement disorders in NMD are: dystonia, myoclonus, chorea, tremor and parkinsonism (Fig. 1). The primary goal of this article is, departing from the literature and a large personal series, to describe the types of movement disorders most frequently observed in NMD and to discuss their clinical value in the setting of specific types of NMD.
 ...
PMID:Movement disorders in neuro-metabolic diseases. 2001 70