Neurological system cranial nerves

Central and/or peripheral nervous system involvement is one of the most frequent features, often resulting in the neonatal period in drowsiness, poor sucking, severe hypotonia, abnormal movements, seizures, respiratory distress, and fatal keto-acidotic coma with lactic acidosis [3]. To these severe conditions echo late-onset diseases now frequently attributed to or associated with mitochondrial OXPHOS defects, such as Alzheimer s or Parkinsons disease [10]. Major neurological symptoms, in variable combinations, involve trunk hypotonia, cranial nerve and brainstem involvement (with abnormal eye movements, ophthalmoplegia, recurrent apneas), cerebellar ataxia, myoclonia, seizures, pyramidal syndrome, peripheral neuropathy, poliodystrophy, and leukodystrophy infections [27,28]. A diffuse impairment of the cerebral white matter (leukodystrophy) mostly results in motor disturbance with mental retardation and low incidence of seizures. 

Neurologic pathways in the sympathetic nervous system originate from the thoracic (T1 to T12) and the upper lumbar segments (LI and L2) of the spinal cord. Neurologic pathways in the parasympathetic nervous system originate from cranial nerves III, VII, IX, and X, from the brainstem, and the sacral segments S2, S3, and S4 from the spinal cord. This is why the parasympathetic nervous system is also known as the craniosacral division of the autonomic nervous system. 

Neurological involvement is noted in 50% to 78% of patients (26,27). Mononeuritis multiplex is the most frequent ( 70% patients with peripheral neuropathy) at CSS onset whereas symmetrical polyneuropathy can be seen in up to 30% of patients (26,27). Central nervous system (CNS) involvement (cranial nerves palsies, cerebral hemorrhage or infarction, convulsions, coma, and psychiatric features) is rarely seen (16). 

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