Conjugate Deviation of the Eyes after Cannabis Indica Intoxication.

Cannabis indica or Sativa (also known as Indian hemp and marihuana) is an easily available cheap intoxicant used by certain communities in India. Cannadiol (CG1H3002) and cannabinol (C21H2602) in pure crystalline forms have been isolated from it (Adams, 1942). A highly effective compound similar to tetrahydrocannabinol (Adams, 1942) has been isolated from the natural source (Loewe and Modell, 1941). The principal site of action of Cannabis indica is the brain, particularly the cerebral cortex (Chopra, Chopra, and Chopra, 1942; Allentuck, 1944; Loewe, 1944); it causes excitation in some cases, and depression of higher functions in others. After ingestion of the drug the subject experiences a feeling of euphoria and exaltation with extravagant dream fantasies and loses his sense of time (Walton, 1938), but acute poisoning by Cannabis indica is extremely rare (Walton, 1938) and no fatality has been reported (Walton, 1938; Loewe, 1944; Sollmann, 1957). The effect is usually transitory and wears off in 3 to 5 hours, though it may persist for 12 hours or more with no lasting ill-effects (Loewe, 1944). The margin between the effective and fatal dose is wide, the intravenous fatal dose for dogs being a hundred times the narcotic dose (Sollmann, 1957). MiesesReif (1936) reported temporary blindness, ulcers of the cornea, and swelling of the lids in a woman who worked in a field of Cannabis indica. Other ocular signs include congestion of the conjunctiva and lids (Allentuck, 1944; Walsh, 1947; Sollmann, 1957), dilatation of the pupils (Walsh, 1947; Sollmann, 1957) corneal areflexia (Loewe, 1944), and visual hallucination (Chopra and others, 1942; Allentuck, 1944; Walsh, 1947). The case of Cannabis indica poisoning presented below is interesting because of the conjugate deviation of the eyes, not reported before, and the long duration of the intoxication.