In opium, immovably and symmetrically contracted.
In uræmia, dilated and sluggish.
In diabetes, equal but dilated. React to light.
In doubtful cases an examination of the disks may clear up the diagnosis. The presence of albuminuric retinitis, optic neuritis and atrophy (diabetes and uræmia), retinal hæmorrhages (injury), offer material diagnostic aid.
The tongue should be examined for such biting as is observed in epilepsy. The odour of the breath is investigated—the sickly smell of alcohol, the sweetish odour of uræmia, the peculiar smell of opium, the chloroform-like smell of diabetes.
The appearance of the face may be suggestive. The unilateral facial palsy of trauma and apoplexy; the stertorous respiration, puffing out of the cheeks, and general turgidity of compression, uræmia, apoplexy and deep alcoholism; the quiet breathing and pale face of concussion, opium poisoning, and of post-epileptic and diabetic coma.
The urine should be examined for albumen and sugar, and the body and lower extremities for œdema.
The extremities are investigated with respect to unilateral palsy, a condition only present in trauma and apoplexy. General convulsions point to injury, uræmia, and epilepsy. Resistance to manipulation is suggestive of alcoholic excess. Unilateral palsy may be associated with corresponding alteration in the deep reflexes.
The pulse-rate and the condition of the arteries supply valuable evidence. The coats may be atheromatous, whilst the slow, full pulse is strongly suggestive of compression, apoplexy, and alcoholism.
The temperature should be taken on both sides of the body. A rise of temperature is usually dependent on brain injury, apoplexy, and alcoholism. In opium poisoning, uræmia, and epilepsy the temperature is more likely to be normal or subnormal. In pontine hæmorrhage, hyperpyrexia is commonly observed.