[Total right hemispherectomy: neurophysiological study after twenty-six years]

Area of Science:

• Neuroscience
• Neurology
• Neurosurgery

Background:

• A patient underwent a total right hemispherectomy at age 13 for a tumor.
• 26 years post-surgery, the patient presented with equilibrium disturbances, urinary incontinence, and reduced motor impulses.

Observation:

• Computed tomography suggested normal pressure hydrocephalus, but intracranial pressure monitoring ruled out cerebral obstruction.
• Clinical examination revealed intact sensory appreciation on the left side of the body and visual object detection in a supposedly blind hemifield.
• Auditory function tests demonstrated excellent stereoaudiometry and dichotic listening perception.

Findings:

• Somatosensory evoked potentials showed normal contralateral and even ipsilateral responses in the left hemisphere, suggesting alternative sensory processing pathways.
• Auditory evoked potentials had minor anomalies, with bilateral wave VI indicating median geniculate pathway activity.
• Visual function tests confirmed good left photomotor reflexes and object detection in the anopsic hemifield.

Implications:

• The findings suggest remarkable neuroplasticity and the potential for compensatory mechanisms in the remaining hemisphere after extensive brain surgery.
• This case provides insights into the adaptability of sensory pathways, particularly spinoreticulothalamic tracts, in hemispherectomized individuals.
• The study underscores the importance of comprehensive neurophysiological assessments to understand functional recovery and adaptation post-hemispherectomy.