Lateral medullary syndrome (also called Wallenberg's syndrome and posterior inferior cerebellar artery syndrome) is a disease in which the patient has difficulty with swallowing or speaking or both owing to one or more patches of dead tissue (known as an infarct) caused by interrupted blood supply to parts of the brain.
This syndrome is characterized by sensory deficits affecting the trunk and extremities on the opposite side of the infarct and sensory and motor deficits affecting the face and cranial nerves on the same side with the infarct. Other clinical symptoms and findings are ataxia, facial pain, vertigo, nystagmus, Horner's syndrome, diplopia and dysphagia. The cause of this syndrome is usually the occlusion of the posterior inferior cerebellar artery (PICA) at its origin. The affected persons have difficulty in swallowing (dysphagia) resulting from involvement of the nucleus ambiguus, and slurred speech (dysphonia, dysarthria). Damage to the spinal trigeminal nucleus causes absence of pain on the ipsilateral side of the face, as well as an absent corneal reflex. The spinothalamic tract is damaged, resulting in loss of pain and temperature sensation to the opposite side of the body. The damage to the cerebellum or the inferior cerebellar peduncle can cause ataxia. Damage to the hypothalamospinal fibers disrupts sympathetic nervous system relay and gives symptoms analogous to Horner's syndrome.
It is the clinical manifestation resulting from occlusion of the posterior inferior cerebellar artery (PICA) or one of its branches or of the vertebral artery, in which the lateral part of the medulla oblongata infarcts, resulting in a typical pattern. The most commonly affected artery is the vertebral artery, followed by the PICA, superior middle and inferior medullary arteries.
The outlook for someone with lateral medullary syndrome depends upon the size and location of the area of the brain stem damaged by the stroke. Some individuals may see a decrease in their symptoms within weeks or months. Others may be left with significant neurological disabilities for years after the initial symptoms appeared
Treatment for lateral medullary syndrome is symptomatic. A feeding tube may be necessary if swallowing is very difficult. Speech/swallowing therapy may be beneficial. In some cases, medication may be used to reduce or eliminate pain. Some doctors report that the anti-epileptic drug gabapentin appears to be an effective medication for individuals with chronic pain. The small size of the affected PICA does not lend itself to surgical recanalisation