Forebrain diseases of the horse: relevant examination techniques and illustrative video segments.

1. ABSTRACT The forebrain comprises the diencephalon (thalamus and hypothalamus) and the cerebral hemispheres. Both intrinsic and learned behaviors are forebrain-dependent as are central perception of vision and touch. Forebrain injury thus may cause demented behavior, central blindness and reduced response to touch. Seizures usually arise in the forebrain. Careful evaluation of mentation, menace responses and vision, reaction to touching the nasal septum, in conjunction with other parts of the neurologic examination, should provide accurate localization of forebrain lesions. Recognition of signs of forebrain dysfunction is an important step in the processes of diagnosis and treatment.