Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0004134 (ataxia)
 15,886 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A 21-year-old woman, who had no particular familial history, was admitted to our hospital because of hand tremor and gait disturbance. On neurological examination, she showed muscle weakness in the proximal extremities. There was an ataxia on heel-to-shin testing. Action and postural myoclonus involving the extremities were also noted. In addition, with dorsiflexion of the hands, asterixis-like movement was manifested. Pyruvate was 1.0 mg/dl and lactate was 24.1 mg/dl in cerebrospinal fluid. Brain CT scan revealed mild cerebellar atrophy. EEG showed synchronous diffuse slow wave. Median nerve SEPs showed a large N20-P25 component (20 microV). Median nerve C-reflex was not evoked. With dorsiflexion of the hands, the asterixis-like movement was induced with brief cessation of surface EMG activity in the forearm muscles, as shown by the accelerometer trace. Biopsy specimens of the biceps brachii muscle revealed numerous ragged-red fibers. By PCR-RFLP method with use of a mismatched primer, we analyzed mitochondrial DNA extracted from peripheral leukocytes. The A to G mutation at nucleotide position 8,344 in a tRNA(Lys) gene of a mitochondrial genome was detected. In this patient, clonazepam was effective on the asterixis-like movements. From existence of positive myoclonus, giant SEPs and efficacy of clonazepam, we considered this movement to be negative myoclonus. Our study indicated the possibility that such an involuntary movement could be induced by certain posture in patients with MERRF.
 ...
PMID:[Myoclonus epilepsy associated with ragged-red fibers--report of a patient with negative myoclonus]. 149 Mar 14

Spontaneous (nontraumatic) midbrain hemorrhage (SMH) is an uncommon condition whose diagnosis is greatly assisted by the use of cranial computerized tomography. Of 18 cases described in the English language literature, only two were diagnosed without the aid of CT. We report five cases of SMH in five normotensive patients. Vertical gaze palsies were noted in four patients, headache in four, pupillary dysfunction in four, mild hemiplegia in two, unilateral ataxia in two, and unilateral asterixis in one. The diagnosis of SMH had not been considered before CT scanning in any of these patients. All patients had partial to complete recovery. Cerebral angiography in each case showed no abnormalities in the area of the hemorrhage.
 ...
PMID:Spontaneous midbrain hemorrhage. 231 72

Clinical and electrical evidence of peripheral neuropathy may result from long term treatment with phenytoin or barbiturates, especially in combination, or after repeated exposure to toxic blood concentrations of either drug. Prolonged acute toxicity with phenytoin may rarely lead to permanent residual ataxia. Reversible dystonia may occasionally be precipitated by phenytoin or carbamazepine; asterixis by phenytoin, barbiturates or carbamazepine; and, more commonly, tremor by valproate. All the major anticonvulsant drugs, especially in combination, can produce occasional subacute cognitive or behavioural syndromes. In varying degrees, the drugs also impair attention, concentration, memory, mental speed or processing, or motor speed. Possible mechanisms of impaired mental function include neuronal damage, or disturbance of folic acid, monoamine or hormonal metabolism. The relative influence on neurological or psychological function is an important factor in the choice of anticonvulsant drug for the treatment of epilepsy.
 ...
PMID:Adverse neuropsychiatric effects of anticonvulsant drugs. 286 Oct 75

Dementia--a syndrome of acquired intellectual deterioration--is an etiologically non-specific condition which is permanent, progressive, or reversible. In the evaluation of demented patients, a careful exposure history will determine the possible role of drugs, metals, or toxins. The physical examination may reveal focal deficits in cases of intracranial mass lesions and spasticity or ataxia of the lower limbs if hydrocephalus is present. Coexistance of dementia and peripheral neuropathy usually indicates a toxic or metabolic disorder. Asterixis, myoclonus, and postural tremor are common in toxic-metabolic dementias, while resting tremor, choreoathetosis, and rigidity occur in progressive extrapyramidal disorders. EEG is focally abnormal in cases of cerebral mass lesions and exhibits generalized slowing in toxic-metabolic encephalopathies. CT will aid in the identification of hydrocephalus, subdural hematomas, and intracranial mass lesions. A thorough laboratory evaluation including complete blood count, erythrocyte sedimentation rate, electrolytes, blood urea nitrogen and blood sugar, liver and thyroid tests, calcium and phosphorus levels, B12 and folate levels, serum copper and ceruloplasmin, VDRL, chest X-ray, electrocardiogram, and lumbar puncture may demonstrate treatable disorders that are adversely affecting intellectual function. Elderly individuals are particularly susceptible to the effects of toxic or metabolic disorders, and a mild dementia might be exaggerated by relatively minor fluctuations in metabolic status. Treatable causes of dementia should be considered in all demented patients.
 ...
PMID:[Treatable dementia syndromes]. 358 48

Dementia, a syndrome of acquired intellectual deterioration, is an etiologically nonspecific condition that can be permanent or reversible. When evaluating demented patients, a careful exposure history will determine the possible role of drugs, metals, or toxins. Physical examination may reveal focal deficits in cases of intracranial mass lesions and spasticity or ataxia of the lower limbs if hydrocephalus is present. Coexistence of dementia and a peripheral neuropathy usually indicates the existence of a toxic or metabolic disorder. Depressed mood, sleep disturbance, anorexia, impotence, constipation, and psychomotor retardation indicate the presence of a depressive syndrome. Asterixis, myoclonus, and postural tremor are common in toxic-metabolic dementias, whereas resting tremor, choreoathetosis, or rigidity occur in progressive extrapyramidal disorder. EEG is focally abnormal in cases of cerebral mass lesions and shows generalized slowing in toxic-metabolic encephalopathies. CT will aid in the identification of hydrocephalus, subdural hematomas, and intracranial mass lesions. A thorough laboratory evaluation including complete blood count, erythrocyte sedimentation rate, electrolytes, blood urea nitrogen and blood sugar, liver and thyroid function tests, serum calcium and phosphorus levels, B12 and folate levels, serum copper and ceruloplasmin, VDRL, chest X-ray, electrocardiogram, and lumbar puncture may demonstrate treatable disorders that are adversely affecting intellectual function. Elderly individuals are particularly susceptible to the effects of toxic or metabolic disorders, and a mild dementia may be exaggerated by relatively minor fluctuations in metabolic status. Treatable causes of dementia should be sought in all demented patients.
 ...
PMID:Treatable dementias. 635 58

Sodium valproate was administered to 38 patients, admitted to our unit in the last 18 months, and chosen because they had: (1) poor control of their seizures; (2) therapeutic concentrations in their plasma of at least two major antiepileptic drugs. In 8 of them, a therapeutic dosage of VPA caused modifications of the state of consciousness ranging from coma to drowsiness and stupor. These patients also showed gastrointestinal disturbances, asterixis, ataxia, tremor and a worsening of EEG abnormalities. The side effects of the drug were constantly associated with increased concentration of blood ammonia. Better penetration of ammonia into the CNS of patients undergoing frequent seizures and possibly having imperfectly functioning biological barriers, could explain our observations. In view of the unusually high percentage of patients suffering from serious VPA side effects, it is probably advisable to carefully monitor ammonemia in the first few days of VPA therapy in every patient treated with multiple anticonvulsants.
 ...
PMID:Hyperammonemia and valproate-induced alterations of the state of consciousness. A report of 8 cases. 642 61

Six epileptic patients are described to whom the addition of Valproic Acid (VPA) to a previously unsatisfactory antiepileptic treatment caused a toxic encephalopathy. This was characterized by alterations of the state of consciousness in all patients a few days after the beninning of the treatment with VPA. These ranged from a marked drowsiness to coma and were often associated with gastrointestinal and neurological (ataxia, asterixis) symptoms. In all cases very high blood ammonia values were found and the EEGs showed a diffuse slowing down of the activity. After the discontinuation of the drug the toxic symptoms quickly ceased and ammonia values returned to the normal values. It is hypothesized that the interference of VPA on the metabolism of ammonia could play an important role in the pathogenesis of the VPA-induced toxic encephalopathy.
 ...
PMID:[Alterations of the state of consciousness induced by valproic acid: 6 case reports]. 643 99

A 58-year old right-handed man with chronic non valvular atrial fibrillation developed an acute left upper limb ataxia with transient numbness and mild motor impairement. Two weeks later, there was a severe degree of ataxia of the left upper limb and prominent asterixis of the left hand. CT scan and MRI showed a small parietal infarct. Initial median nerve somatosensory evoked potentials (SEPs) showed mild impairement of right parietal responses with absent right frontal SEPs P22 and N30. Two months later, parietal responses were normal but right frontal SEPs P22 and N30 remained abolished while ataxia of left upper limb persisted. Electromyographic activity recorded at the same time showed periodic involvement of the left hand distal tonus. These finding suggested that both ataxia and asterixis were due to a single postcentral infarct. Frontal SEP components are known to convey proprioceptive inputs which could be received by neocerebellar afferent pathways. Generators of these components are presumably located in premotor cortex and can be activated through parietofrontal connections. In our case it can be assumed that the parietal infarct involved these connections, which are mainly implied in the regulation of postural tonus of the distal upper limbs, and simultaneously impaired neocerebellar afferent pathways resulting in the emergence of parietal ataxia.
 ...
PMID:[Ataxic monoparesis of the upper limb and suspension of the tonus caused by parietal lesion]. 823 23

We prospectively studied motor symptoms in 32 patients with CT- or MRI-proven acute pure parietal stroke. A transient, mild, 'pseudoparesis' of the hand (90%), was noted, improved by visual attention and prompting, associated with non-awareness of muscle power (53%), transient soft pyramidal signs (50%), unilateral akinesia (100%) and motor hemineglect (37%) in non-dominant lesions. Lower motoneurone-type atrophy was not observed in this acute phase. We called 'poikilotonia' the striking unpredictable variations in muscle tone, ranging from extreme hypertonia to hypotonia, found in all patients. When maintaining postures, patients showed large oscillations (100%), laterodeviation or levitation of the arm (60%), especially in the case of large or posterior lesions, or, occasionally (3%), motor persistence or even hemicatalepsy (3%). Limb kinetic and manipulatory apraxia, with inadequate organization and anticipation of motor sequences and synergies, motor arrests, perplexity, unrecognizable gestures and loss of bimanual coordination, was a constant finding (100%). Other apraxias (62%) and difficulty in copying intransitive gestures of the hand (84%) were associated with posterior lesions involving the supramarginal gyrus. When reaching towards objects, all patients showed abnormal anticipatory hand shaping, but visuomotor ataxia (3%) was only seen with bilateral posterior stroke. Sensory (70%) or pseudocerebellar (4%) ataxia, was seen in both anterior and posterior lesions. Avoidance behaviors (34%) were not uncommon, but had no localizing value. Of the dyskinesias, hand dystonia (84%) was frequent, but athetosis (16%), asterixis (15%), postural tremor (15%), myoclonus (9%) and stereotypia (9%), were uncommon. The abnormal eye movements were unilateral hypo-akinesia of exploratory saccades (43%), abnormal ipsilateral pursuit and contralateral optokinetic nystagmus in the case of posterior lesions, and oculomotor apraxia with bilateral posterior lesions. In conclusion, parietal motor syndrome can be recognized during bedside examination, and probably reflects the loss of multiple sensory feedback to motor programs, especially those directed to the extrapersonal space.
 ...
PMID:Parietal motor syndrome: a clinical description in 32 patients in the acute phase of pure parietal strokes studied prospectively. 987 53

A huge number of neurological disorders are associated with myoclonus. This paper describes these disorders whose diagnosis partly relies on the presence of myoclonus. The diagnostic approach is related to certain clinical features of myoclonus, which, after their integration in the clinical context, help orientate towards diagnosis. Myoclonus is frequent during dementia. Although its presence is well-known to take part in the diagnosis of Creutzfeldt-Jakob disease (CJD), myoclonus can also be present to a significant degree in Alzheimer's disease and Lewy body dementia (LBD), which raises a diagnostic issue. Both its clinical and electrophysiological features may help differential diagnosis, given that myoclonus with fast-evolving dementia and focal neurological signs should favor the diagnosis of CJD. Myoclonus in a context of progressive ataxia suggests one clinical form of the Ramsay-Hunt syndrome (progressive myoclonic ataxia, PMA), whose most frequent causes are: coeliac disease, mitochondriopathies, some spino-cerebellar degenerations, and some late metabolic disorders. In addition to ataxia and myoclonus, the presence of opsoclonus directs diagnosis toward the opsoclonus-myoclonus syndrome (OMS), whose origin, in adult, is idiopathic or paraneoplastic. Palatal tremor (myoclonus) with ataxia may represent either a sporadic pattern, which often reflects the evolution of degenerative or lesional disorders, or a familial pattern in some degenerative affections or metabolic diseases. Of more recent knowledge is the association of progressive ataxia, myoclonus, and renal failure, which corresponds to a recessive autosomic disease. In a context of encephalopathy, myoclonus is frequent in metabolic or hydro-electrolytic disorders, and in brain anoxia. One should distinguish these various forms of myoclonus which may occur in the acute post-anoxic phase, from those occurring as sequels at a later stage, i.e. the Lance and Adams syndrome whose clinical aspects are also multiple. Myoclonus is less frequent during toxic or drug exposures. Irrespective of its acute or insidious onset, Hashimoto's encephalopathy is accompanied by myoclonus and tremor. Myoclonus may also be present during encephalic and/or spinal infectious disorders. Myoclonus with focal neurological signs may be observed in thalamic lesions, responsible for unilateral asterixis or unilateral myoclonus superimposed on dystonic posture. Segmental spinal myoclonus or propriospinal myoclonus may be associated with several spinal-cord disorders. Myoclonus associated with peripheral nerve lesions is exceptional or even questionable for some of these.
 ...
PMID:Symptomatic myoclonus. 1733 75


1 2 Next >>