Consequences of brainstem white matter lesions for dizziness and imbalance. The brainstem is "tightly packed", and one would expect that brainstem lesions, even small ones, could have serious consequences to balance, motor control, and function of the nerves in the head (e.g. cranial nerves). Methods: Subjects were included in a prospective cohort of patients with CIS. Patients underwent brain MRI within 3 months after CIS onset. spinocerebellar pathway localises the lesion to the ipsilateral lateral brainstem. right-sided facial numbness with loss of the corneal reflex: Sensory nucleus of the 5th cranial nerve localises the lesion to the ipsilateral lateral brainstem. the lesion involves the pons affecting the ipsilateral CN7.
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The basilar artery branches are paramedian, supplying the area of the pons close to the brain stem lesions, the short circumferential branches that supply the lateral two-thirds of the pons, the long circumferential branches that are the supero- and anteroinferior cerebellar arteries, and several interpeduncular branches that arise at the bifurcation of the basilar artery and supply the subthalamic and high midbrain regions.
Unilateral Brain-Stem Lesions | JAMA Neurology | JAMA Network
Although most brainstem syndromes are due to vascular or inflammatory demyelinating brain stem lesions, an increasing proportion are shown on MRI to be due to cavernomas, which may or may not calcify and which were impossible to diagnose before modern imaging. The management of such cavernomas is difficult and may involve surgery or stereotactic radiotherapy.
There may also be motor hyperactivity. The differential diagnosis includes hyperthyroidism, diabetes mellitus, a tumour in the region of the brain stem lesions ventricle, such as a malformation of the great vein of Galen, and a hypothalamic tumour.
Unilateral Brain-Stem Lesions
There may often be optic atrophy and rarely nystagmus. Investigation may show an elevated serum growth hormone and an MRI will show a hypothalamic mass lesion. Although brain stem lesions if there is a significant structural pathology, the cerebrospinal fluid may contain malignant cells or an excess of human chorionic gonadotropin in the case of germinoma.
Thalamic syndrome Originally described by Dejerine and Roussy inthalamic pain has a brain stem lesions distressing quality.
Sometimes spontaneously, but commonly after a recognized hemiplegic and hemianaesthetic stroke, the patient develops altered brain stem lesions in a hemisensory distribution together with unpleasant dysaesthetic burning pain thalamic pain.
It would be interesting to see in future studies if this technique could be used as part of a surrogate outcome to monitor MS progression, specifically of the brainstem.
The vestibular evoked myogenic potentials VEMP score: Time of flight maximum intensity of brain stem lesions images panels D and E show residual segmental sub-occlusive stenosis of the basilar artery white arrow in D and E.
In the brain stem lesions period, however, the development of this network may not be complete and children with hypoxic-ischemic encephalopathy in the perinatal period are susceptible to damage in the brainstem tegmentum[ 7 ]. Tegmental lesions are columnar-shaped on the coronal planes, bilateral and usually symmetrical, with specific involvement of caudal pons and medulla oblongata and are associated with oral motor dysfunction and gavage feeding[ 7 ] Figure 2.
A day-old neonate with history of brain stem lesions injuried.
Unilateral Brain-Stem Lesions
Coronal A and B and axial C-E T2- weighted images show bilateral and symmetric hyperintensities black arrows at the level of the pontine tegmentum. T1-weighted axial images F-H show hypointense signal at the same sites. Vascular malformations also are encountered in the brainstem of children. These include low flow malformations such as developmental venous anomaly, cavernous hemangioma and capillary telangiectasia and high flow malformations such as arterio-venous malformation.
The MRI pattern is characteristic for each of these vascular entities and commonly the diagnosis is not challenging. The MR brain stem lesions intensity and morphology at conventional imaging are identical to those observed in the adult population[ 3 ].
Mitochondrial diseases include a wide range of clinical syndromes associated with deficits of the oxidative phosphorylation, caused by partial or complete deficits of one or more enzymatic complexes of the respiratory chain[ 12 ].
Hereditary transmission may be autosomal recessive, autosomal brain stem lesions, X-linked or maternal[ 13 ]. The defect of the mitochondrial respiratory chain may, in fact, be caused by genetic mutations of either nuclear DNA or mitochondrial DNA[ 14 - 17 ].
Metabolic vulnerability is an brain stem lesions issue for the involvement of the brainstem in these diseases[ 18 ]: In fact, cells and tissues with high metabolic demand are more susceptible to specifically incur damage due to their inability or incomplete ability to reduce oxygen and finally produce ATP energy molecules[ 19 ].
The clinical presentation of these diseases is multi-systemic because different tissues and organs are involved.
Brain stem lesions diagnosis is challenging due to the extreme genetic and phenotypic heterogeneity. Due to their pathogenesis, the brainstem lesions are symmetrical, sometimes confined to the same specific location bilaterally.
The substantia nigra, mainly the pars reticulata, the medullary and pontine tegmentum and the inferior colliculi are reported as the most frequent sites[ 20 brain stem lesions. The inferior olivary nuclei are often involved, although this is not seen in children who die before 1 year of age[ 20 brain stem lesions.
The loss of Purkinje cells and cerebellar involvement is, in fact, more characteristic of other mitochondrial encephalopathies such as myoclonic epilepsy with ragged-red fibers MERRFmitochondrial encephalopathy, lactic acidosis and stroke-like episodes MELAS and Kearns-Sayre syndrome[ 23 ].