As alcoholism is 3-4 times more frequent in men than in women, incidence of Wernicke encephalopathy is greater in males than in females. Average age at onset among adults is 50 years. Wernicke encephalopathy is found largely in persons with alcoholism, although it is not restricted to this group. Thiamine depletion can occur because of poor diet or impaired absorption. Only a third of patients with acute Wernicke encephalopathy present with the classic clinical triad.
Ocular abnormalities are the hallmarks of Wernicke encephalopathy.
Horizontal nystagmus and paralysis of lateral rectus muscles are common. Less frequently noted are pupillary abnormalities such as sluggishly reactive pupils, ptosis, and anisocoria. Global confusional state Apathy Impaired awareness of the immediate situation Spatial disorientation Inattention Inability to concentrate Ataxia, the loss of equilibrium seen in the early stages of the disease, results from vestibular paresis, which is uniformly found, yet often poorly appreciated. The wide-based ataxic gait seen in the subacute and chronic phases of the illness results from cerebellar dysfunction, either alone or combined with vestibular dysfunction. Hypothermia, from involvement of the temperature-regulating center, is characteristic.