Myoclonic twitching

Typical symptoms of lithium intoxication are summarized in Table 2 [122-127]. The clinical picture of hthium intoxication is dominated by neuromuscular and cerebral symptoms in mild cases apathy, muscle weakness, tremor, and unsteady gait are seen. In more severe cases speech disturbances, myoclonic twitching, coma and convulsion can occur. Pulse irregularities and circulatory collapse may supervene. Lithium often causes T-wave flattening or inversion on the electrocardiogram, but clinically important cardiovascular effects are rare, with sinus-node dysfunction reported most often [123]. Residual neurological sequelae consisting of cerebellar dysfunction with ataxia, neuropathy and supra-bulbar symptoms are not unusual. 

CNS- Dizziness vertigo headache overactivity hyperreflexia tremors muscle twitching mania hypomania jitteriness confusion memory impairment sleep disturbances including hypersomnia and insomnia weakness myoclonic movements fatigue drowsiness restlessness overstimulation including increased anxiety, agitation and manic symptoms. 

Halothane, isoflurane, and enflurane have similar depressant effects on the EEG up to doses of 1-1.5 MAC. At higher doses, the cerebral irritant effects of enflurane may lead to development of a spike-and-wave pattern and mild generalized muscle twitching (ie, myoclonic activity). However, this seizure-like activity has not been found to have any adverse clinical consequences. Seizure-like EEG activity has also been described after sevoflurane, but not desflurane. Although nitrous oxide has a much lower anesthetic potency than the volatile agents, it does possess both analgesic and amnesic properties when used alone or in combination with other agents as part of a balanced anesthesia technique. 

A 35-year-old woman, who was admitted for elective laparotomy and ileostomy formation was given patient-controlled analgesic with pethidine for postoperative analgesia (8). The device was set to deliver 20 mg of pethidine with a 5-minute lock-out period and no hourly limit. At 4 hours postoperatively she did not have pethidine-related neurotoxicity, but at 23 hours she had myoclonic jerks and facial twitching followed by a brief generalized tonic-clonic seizure and postictal sequelae. The pethidine was withdrawn and there was no further seizure activity. She had self administered a total of 2700 mg. The norpethidine concentration was 1.8 pg/ml. 

Myoclonic encephalopathy (intermittent spasm or twitching of muscles)... 

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