Impact of surgical treatment on tremor due to posterior fossa tumors

Severe Bilateral Kinetic Tremor Due to Unilateral Midbrain Lesions

Background

The dentatothalamic tract connects the dentate nucleus of the cerebellum with the contralateral thalamus and plays a major role in the pathogenesis of tremor. Unilateral lesions of the dentatothalamic pathway may affect its ipsilateral predecussational or its contralateral postdecussational course, which results either in ipsilateral or in contralateral tremor.

Case Report

Here, we present two patients with a unilateral midbrain lesion resulting in bilateral tremor. Both patients presented with severe kinetic tremor.

Discussion

The corresponding unilateral mesencephalic lesion affected both the ipsilateral predecussational and the ipsilateral postdecussational dentatothalamic tract originating from the contralateral dentate nucleus, which is very unusual and has not been outlined clearly before.

Postural tremor as a manifestation of spontaneous intracranial hypotension

Spontaneous intracranial hypotension (SIH) is a syndrome caused by low cerebrospinal fluid (CSF) pressure due to leakage of CSF. Clinically, orthostatic headache, neck pain, nausea, emesis, interscapular pain, diplopia, dizziness, changes in hearing, visual blurring and radicular upper extremity symptoms are most frequently observed. We describe a 57-year-old man with SIH who presented with postural tremor. CSF leakage was revealed by cranial MRI. Lumbar puncture identified low CSF pressure and intrathecal gadolinium enhanced MR cisternography showed diffuse CSF leakage in the thoracolumbar region. The patient underwent epidural blood patching, which resulted in complete resolution of postural tremor within 2 months.

Hemiparkinsonism due to a pontomesencephalic cavernoma: improvement after resection. Case report

Cavernous angiomas of the upper brainstem causing hemiparkinsonism are very rare. Due to their difficult-to-reach localization, brainstem cavernomas, in particular those in anterior locations, continue to present a therapeutic challenge. The authors report on a 16-year-old boy with a pontomesencephalic cavernoma who developed hemiparkinsonism and hemiparesis after hemorrhage. After complete surgical removal of the pontomesencephalic cavernoma via a pterional transsylvian approach, his symptoms resolved. Although pontomesencephalic cavernomas occupying the ventral portion of the brainstem are regarded as problematic for resection, the pterional transsylvian approach provides an excellent route for removal of cavernomas that are in contact with the ventral surface of the midbrain in the interpeduncular cistern. Surgical removal of this type of lesion is recommended because resolution of clinical symptoms, including hemiparkinsonism, can be achieved.