A monofocal pontine lesion

Abstract

The patient was admitted for confusion and a resultant tracheal laceration sustained after her fall which was complicated with subcutaneous emphysema and infection. Diagnostic studies revealed normal serum electrolytes, cerebrospinal fluid study, vitamin B12 level, and tests for rheumatological diseases. Chronic alcoholism was felt to be the cause of the central pontine myelinolysis (CPM). The patient improved significantly with antibiotics and surgical tracheal repair and was discharged with minimal memory residual deficits. Repeat MRI of the brain more than 6 months later showed decreased but persistent hyperintensity in the midpons (Fig. 1). CPM is most commonly associated with: alcoholism, 39.4% of patients; rapid reversal of hyponatremia, 21.5%; and liver transplantation, 17.5%. Prognosis for CPM is reported to be invariably fatal but patients with complete recovery with mild impairment have been seen. Three subtypes of these brain demyelinating diseases are known: (i) CPM, confined to the pons; (ii) extrapontine myelinolysis (EPM); and (iii) osmotic demyelinating syndrome (ODS), in which CPM and EPM are both present. Adult pontine gliomas are rare tumors that usually present clinically with gait disturbance, headaches, weakness of limbs, and cranial nerve involvement. MRI findings include a non-enhancing diffusely infiltrative mass, enhancing localized mass, and isolated tectal tumor. The absence of these findings in our patient made the diagnosis of a pontine glioma unlikely. Pontine infarctions usually present with findings that may include ipsilateral peripheral cranial nerve palsies, contralateral movement disorders, sensory disturbances, and pure motor hemiparesis or hemiplegia. MRI findings typically include a well-demarcated hyperintensity in the pons on T2-weighted MRI with a corresponding hypointensity on T1-weighted MRI. Multiple sclerosis is a chronic, persistent inflammatory–demyelinating disease of the central nervous system that typically presents as an acute clinically isolated syndrome attributable to a monofocal or multifocal demyelinating lesion,