The clinical hallmark of<unk>  is ataxia due to sensory polyneuropathy. Blood tests are performed to rule out other causes and to confirm an elevated level of vitamin<unk>  with an absence of hypophosphatasia. Examination does not typically show signs of a motor deficit, dysfunction of the autonomic nervous system or impairment of the central nervous system, although in severe cases motor and autonomic imparement can occur. When examined, patients typically have diminished reflexes (hyporeflexia), such as a diminished response when performing an ankle jerk reflex test. Nerve conduction studies typically show normal motor conduction but decrease in large sensory wave amplitude in the arms and legs. Needle electromyography studies generally reveal no signs of denervation. Classification<unk>  is characterized mainly by degeneration of dorsal root ganglion axons and cell bodies, although it also affects the trigeminal ganglia. It is classified as a sensory ganglionopathy due to involvement of these ganglia. In electrodiagnostic testing, it has characteristic non-length-dependent abnormalities of sensory action potentials that occur globally, rather than distally decreasing of sensory nerve action potential amplitudes.<unk>  is predominately a large fiber neuropathy characterized by sensory loss of joint position, vibration and ataxia. Although it has characteristics of small fiber neuropathy in severe cases where there is impairment of pain, temperature, and autonomic functions.
Megavitamin-B6 syndrome
Mercury poisoning
Zinc toxicity
Lead poisoning
Iron poisoning
Copper toxicity
Mercury Poisoning
Chromium toxicity