Sensory ataxia

The syndrome of IgMk paraproteinemia and sensory ataxia is usually encountered in elderly men. Nerve biopsy in these patients shows focal abnormalities in compaction of PNS myelin lamellae, and their IgM paraprotein recognizes epitopes of myelin-associated glycoprotein (MAG) and sulfate-3-glucuronyl paragloboside [24,42]. 

The molecules that constitute vitamin Be are quite safe and there is no established UL. However, the ingestion of industrial doses of pyridoxine, 2-6 g/day for 2 0 months, is known to have caused sensory ataxia and sensory peripheral neuropathy. The senses of touch, temperature, and pain may be altered. Recovery may be slow and incomplete. 

The SN often associated with the Hu antibody is characterized by primary damage to the nerve cell body. The patient suffers from progressive, painful sensory disturbances evolving subacutely, usually with a Rankin score of 3 within 12 weeks of the onset of symptoms [14]. Presenting symptoms include paresthesia, hypoestesia, and very often proprioceptive loss in the affected areas sensory ataxia is common. The upper limbs are often involved [97], The distribution of the SN is often atypical for peripheral neuropathy. The involvement is usually asymmetrical, especially at the onset of symptoms, and may affect the face or upper limbs only. SN is often the presenting symptom of the PEM/SN syndrome, but signs of CNS involvement usually evolve, and autonomic disturbances are common [36]. 

Five people developed nausea, vomiting, diarrhea, abdominal pain, thrombocytopenia, leukopenia, abnormal liver function tests, sensory ataxia, altered consciousness, and persistent peripheral tingling or numbness after drinking infusions of bajiaolian (7). These effects were consistent with podophyllum intoxication. 

In addition to the acute neurotoxic sjmptoms caused by oxaliplatin, about 10-15% of patients develop a moderate neuropathy, particularly after cumulative intravenous doses of 700-800 mg/m. The symptoms of cumulative neuropathy include non-cold-related dysesthesia, paresthesia, superficial and deep sensory loss, and eventually sensory ataxia and functional impairment, which persists between treatment cycles. Most of these sjmptoms usually resolve a few weeks or months after oxaliplatin withdrawal. Lower cumulative doses (for example 510-765 mg/m ) and higher cumulative doses exceeding 1020 mg/m have been associated with incidences of cumulative grade 3 neurotoxicity of 3.2% and 50% respectively (8,9,76,77). In addition, higher cumulative doses, exceeding 1000 mg/m, have been associated with severe, atjrpical neurotoxic sjmptoms, such as micturition... 

A woman with cancer of the ovary and a man with oat cell carcinoma both developed paresthesia of all four Umbs, reduced control of fine movements, and unstable gait after receiving a cumulative dose of 500 mg/m of cisplatin (88). There was distal hypesthesia, with conservation of temperature and pain sensation, areflexia, and sensory ataxia. The woman also had continuous pseudoathetosis. Neurophysiological studies showed absence of peripheral and central sensory potentials and of H-reflexes, normal electromyography, normal motor conduction, and normal mixed silent period. 

One of the most sensitive systems affected by lead exposure is the nervous system. Encephalopathy is characterized by symptoms such as coma, seizures, ataxia, apathy, bizarre behavior, and incoordination (CDC 1985). Children are more sensitive to neurological changes. In children, encephalopathy has been associated with PbB levels as low as 70 pg/dL (CDC 1985). The most sensitive peripheral index of neurotoxicity of lead is reported to be slowed conduction in small motor libers of the ulnar nerve in workers with 30-40 pg/dL lead in blood (Landrigan 1989). Other potential biomarkers of lead suggested for neurotoxicity in workers are neurological and behavioral tests, as well as cognitive and visual sensory function tests (Williamson and Teo 1986). However, these tests are not specific to elevated lead exposure... 

Friedreich s ataxia is caused by an intronic triplet repeat expansion. Friedreich s ataxia is an autosomal recessive disorder characterized by progressive ataxia, nystagmus, distal sensory polyneuropathy and corticospinal tract degeneration. It is caused by an unstable expanded GAA repeat in intron 1 of the frataxin gene on chromosome 9ql3. This diminishes expression of frataxin, a mitochondrial iron-storage protein that participates in free radical metabolism [71]. 

An inevitable consequence of ageing is an elevation of brain iron in specific brain regions, e.g. in the putamen, motor cortex, pre-frontal cortex, sensory cortex and thalamus, localized within H- and L-ferritin and neuromelanin with no apparent adverse effect. However, ill-placed excessive amounts of iron in specific brain cellular constituents, such as mitochondria or in specific regions brain, e.g. in the substantia nigra and lateral globus pallidus, will lead to neurodegenerative diseases (Friedreich s ataxia and Parkinson s disease (PD), respectively). We discuss here a few of the examples of the involvement of iron in neurodegenerative diseases. From more on iron metabolism see Crichton, 2001. 

Some information is available to identify neurological effects in humans from inhalation exposures. The available data indicate that coordination and concentration difficulties, headache, intoxication, and/or anorexia may be induced by inhalation of JP-5 vapor (Porter 1990), headaches may be induced by diesel fuel vapor (Reidenberg et al. 1964), and sensory impairment may be induced by deodorized kerosene vapor (Carpenter et al. 1976). In animals, a few studies were found that document neurological effects from inhalation of fuel oils. Acute inhalation of diesel fuel no. 2 vapor produced behavioral changes, tremors, ataxia, reduced coordination, and increased sensitivity to heat in mice (Kainz and White 1984). 

Inhibition of CNS neurons is the underlying cause of neurological effects such as vertigo, confusion, sensory disturbances, and motor disturbances (tremor, giddiness, ataxia, convulsions). 

Central nervous system effects predominate in acute exposures at massive doses, whereas peripheral neuropathy is more common with lower doses.After cessation of exposure to acrylamide, most cases recover, although the course of improvement can extend over months to years and depends on the severity of exposure. Because peripheral neurons can regenerate and central axons cannot, severely affected individuals may still experience residual ataxia, distal weakness, reflex loss, or sensory disturbance. 

Tremors of the hands and sleep disturbances in the form of vivid dreams, nightmares, and insomnia have been reported in association with the use of amiodarone. Ataxia, staggering, and impaired walking have been noted. Peripheral sensory and motor neuropathy or severe proximal muscle weakness develops infrequently. Both neuropathic and myopathic changes are observed on biopsy. Neurological symptoms resolve or improve within several weeks of dosage reduction. 

The main dose-limiting toxicity is neurotoxicity, usually expressed as a peripheral sensory neuropathy, although autonomic nervous system dysfunction with orthostatic hypotension, urinary retention, paralytic ileus, or constipation, cranial nerve palsies, ataxia, seizures, and coma have been observed. While myelosuppression occurs, it is generally milder and much less significant than with vinblastine. The other potential adverse effect that can develop is the syndrome of inappropriate secretion of antidiuretic hormone (SIADH). 

After 4 months, he developed numbness and paresis of the legs and hyperalgesia at dermatomes T3 and T4. After 10 months he had marked disturbance of proprioception combined with spinal ataxia and an increasing loss of motor bladder control. There was an intraspinal epidural lipoma in the dorsal part of the spine from Tl-10. The fat was removed surgically and within 4 weeks his gait disturbance and proprioception improved, the sensory deficit abated, and the bladder disorder disappeared completely. 

There are three parietal MCA branches anterior, angular and posterior. Anterior parietal or postcentral sulcus artery infarct causes a contralateral sensory loss, with upper limb predominance (pseudo-thalamic syndrome) with involvement of the touch, pain, temperature and vibration senses. Pain and hyperpathia and parietal ataxia can also be present. Conduction aphasia, which is a fluent form of aphasia with disproportionate impairment of repetition, anomia, agraphia and apraxia are present in left hemispheric infarcts while neglect follows in right hemispheric ones. 

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