Cerebellar concussion--three case reports.

Three patients with transient cerebellar dysfunction following head injury are described. Acute cerebellar signs, such as ataxia, nystagmus, and dysarthria, occurred just after trauma and resolved gradually, disappearing in every patient. Cerebrospinal fluid and computed tomography examinations were normal but magnetic resonance imaging and single photon emission computed tomography revealed cerebellar lesions. These findings distinguish cerebellar concussion from cerebellar contusion and suggest that the synergistic effect of trauma and ischemia may be the pathophysiological basis of this unusual syndrome.

Early MR abnormality indicating functional recovery from spontaneous intracerebral hemorrhage.

Magnetic resonance (MR) imaging as an indicator of recovery from hemiparesis was evaluated in 60 patients with spontaneous intracerebral hemorrhage. T2-weighted MR images revealed early MR abnormality (EMA) of the corticospinal tract within 1 week of ictus. Most patients without EMA recovered beyond Brunnstrom's Recovery Stage 3 while only a few patients with EMA did so. Patients with EMA cannot regain motor function because EMA is almost always followed by complete tract degeneration. EMA in the brainstem and poor motor function recovery are closely correlated.

[MR imaging of traumatic cerebellar dysfunction].

Four cases of cerebellar dysfunction following head trauma are presented. Cerebellar signs revealed were those such as dysmetria, dysdiadochokinesis, horizontal nystagmus and ataxia. T2-weighted magnetic resonance (MR) imaging (0.15 tesla, spin-echo method; TR 2000 msec. and TE 100 msec.) revealed focal lesions in these patients, although CT scan failed to demonstrate any changes in the cerebellum. The cerebellar symptoms were maximal immediately after the trauma but improved gradually in two cases. These are compatible with the transient traumatic cerebellar dysfunction postulated by R. C. Cantu in 1969. The pathophysiology of this syndrome, whether it is due to cerebellar concussion or contusion, has not yet been determined. The abnormality of the cerebellum revealed by MR imaging seemed to be contusion rather than concussion. Therefore the authors presume that transient traumatic cerebellar dysfunction is caused by minor cerebellar contusion. In the other two cases, delayed epidural hemorrhage ensued and the symptoms disappeared rapidly after evacuation of the hematoma. In these patients, occurrence of delayed epidural hematoma in the posterior cranial fossa was predicted by MR imaging. The authors regard the lesion as an alarm signal indicating the probable occurrence of infratentorial hematoma.

Analysis of MRI and SPECT in patients with acute head injury.

Traumatic lesions defined by magnetic resonance (MR) imaging were divided into two groups according to findings on computed tomography (CT). This classification reflected difference in the regional cerebral blood flow (rCBF). In the contusional lesions which CT could demonstrate, rCBF varied from hyperperfusion to hypoperfusion, while it was almost always decreased in the lesions which CT could not detect. These results suggest that the former may include a mixture of brain oedema and hyperemia and the latter may imply brain oedema. MR imaging can reveal the minor oedema which CT fails to show in patients with acute head injury.