Table 2a Summary of the clinical signs typically associated with lesions in specific regions of the brain (adapted from Braund, 2003[7])
From: Granulomatous meningoencephalomyelitis in dogs: A review
Fore brain: cerebral cortex and thalamus | Cerebellum |
|---|---|
Seizures | Ataxia |
Behavioural changes (loss of training, failure to recognise owner, aggression, hyperexcitability) | Tremor |
Altered mental status (apathy, depression, disorientation, lethargy, coma) | Hypermetria |
Abnormal movements, postures (circling, pacing, wandering, head-pressing) | Broad-based stance |
Contralateral deficits: postural reactions, vision, menace response, facial sensation | Menace deficits + normal vision |
| Â | No weakness |
Midbrain | Hypothalamus |
Upper motor neuron paresis/paralysis all four limbs or contralateral to lesion | Normal gait |
Postural reaction deficits all four limbs or contralateral to lesion | Altered mental status (disorientation, lethargy, coma) |
Mental depression/coma | Changes in behaviour (aggression/hyperexcitability) |
Ipsilateral oculomotor and trochlear deficits | Bilateral cranial nerve II deficits at optic chiasm |
Hyperventilation | Abnormal movements/postures (tight circling, pacing, |
| Â | wandering, head-pressing, trembling) |
| Â | Abnormal temperature regulation |
| Â | Abnormal appetite |
| Â | Endocrine disturbances |
| Â | Seizures |
Vestibular system (CNS component) | Brain stem |
Head tilt | Ipsilateral hemiparesis/asymmetrical tetraparesis: |
Nystagmus - positional, vertical, horizontal, rotary | Upper motor neuron signs |
Ataxia | Ipsilateral postural reaction deficits |
Postural reaction deficits | Cranial nerve abnormalities: V-VII, IX-XII |
Altered mental status | Altered mental status: depression |
Other cranial nerve signs | Irregular respiration |