Oculomotor disturbance

Chlordecone causes a number of neurotoxic responses in humans and animals exposed to sufficiently high levels. Tremor that is accentuated by intentional acts, sustained postural movement, anxiety, or fatigue has been observed in workers exposed to high levels of chlordecone. Tremorograms have been used to objectively assess the tremor associated with chlordecone exposure in humans (Taylor et al. 1978). An infrared reflection technique and oculography have been used to assess the oculomotor disturbances caused by chlordecone (Taylor et al. 1978). Standard tests for memory and intelligence can be used to determine the presence of encephalopathy, but in the absence of baseline preexposure levels for individuals, subtle changes may be difficult to detect. 

In close vicinity of the ARAS the medial longitudinal fasciculus (MLF) and the oculomotor and trochlear nuclei are situated. Combined coma and oculomotor disturbances points to a brainstem lesion (Parvizi and Damasio 2003). Other clinical symptoms like respiratory pattern, pupillary reflex, and position or movement patterns of the limbs may help localize the site of the lesion. 

Odkvist LM, Larsby B, Fredrickson MF, et al. 1980. Vestibular and oculomotor disturbances caused by industrial solvents. J Otolaryngol 9 53-59. 

Nervous system Fluorouracil can cause acute nervous system toxicity. Acute cerebellar syndrome affects up to 5% of patients and is usually self-limiting after withdrawal. It can occur within weeks to months of starting fluorouracil and presents with ataxia, nystagmus, and dysarthria [77, 78 ]. An encephalopathy can occur rarely and is often associated with markedly raised ammonia concentrations in the absence of underlying liver disease. Ischemic stroke has also been reported and the risk appears to be increased when fluorouracil is combined with cisplatin [60, 79 ]. Other rare adverse reactions include oculomotor disturbances, focal dystonia, parkinsonian syndrome, peripheral neuropathy, and seizures [80 ]. Dihydropyrimidine dehydrogenase deficiency also increases the risk of nervous system toxicity [81" ]. 

Nervous system dizziness, drowsiness, ataxia, confusion, headache, fatigue, blurred vision, visual hallucinations, transient diplopia, oculomotor disturbances, nystagmus, abnormal involuntary movements, peripheral neuritis and paresthesias, depression with agitation, and tinnitus. 

Behavioral Function in Adults. Neurobehavioral testing has revealed effects in adults at PbB levels (i.e., 40-80 pg/dL) below those causing encephalopathy (>400 pg/dL). Evaluations of occupationally exposed adults include several affected parameters at PbB levels between 40 and 80 pg/dL. Disturbances in oculomotor function (saccadic eye movements) in lead workers with mean PbB levels of 57-61 pg/dL were reported in a study by Baloh et al. (1979) with follow-up by Spivey et al. (1980) and in a study by Glickman et al. (1984). Deficits in hand-eye coordination and reaction time were reported in 190 lead-exposed workers (mean PbB level, 60.5 pg/dL) (NIOSH 1974). Most of the workers had been exposed for between 5 and 20 years. A similar study, however, reported no differences... 

Cerebellovestibular and oculomotor dysfunction (with dizziness, diplopia, nystagmus, ataxia), fatigue, and sedation (usually transient) are relatively common. Nausea, vomiting, cognitive dysfunction, headache, myoclonus (including non-epileptic myoclonus), exacerbation of seizures, movement disorders, behavioral or psychiatric disturbances, hyponatremia, and altered cardiac conduction are less common. 

In humans, kava is reported to produce a mild euphoria characterized by happiness, fluent and lively speech, and increased sensibility to sounds (1). It has also been reported to cause visual changes such as reduced near-point accommodation and convergence, increase in pupil diameter, and oculomotor balance disturbances (23). It might even have an antipyretic effect (19). 

In a study on the visual effects produced by kava. Garner and Klinger (1985) noted a reduced near point of accommodation and convergence, an increase in pupil diameter and a disturbance to the oculomotor balance. However, no changes were recorded in... 

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