Visual hallucinations

Off-label prescription of quetiapine in psychiatric disorders

This article reviews the off-label prescription of quetiapine in the treatment of a broad range of psychiatric disorders including obsessive-compulsive disorder, post-traumatic stress disorder, personality disorder, substance abuse, bipolar disorder (now US FDA approved), anxiety and depression. The article highlights the primary reliance on selective serotonin reuptake inhibitors (SSRIs) in the treatment of these disorders (cf bipolar disorder) and the high percentage of patients (30-60%) that do not respond to SSRIs. The studies suggest that low-dose quetiapine shows good tolerability and efficacy in patients diagnosed with these disorders, particularly in the case of treatment-resistant patients that do not respond to primary treatments including SSRIs and cognitive-behavioral therapy. Quetiapine generally appears to be very effective in trauma-related conditions by improving autonomic stability, and decreasing the stress and anxiety response that arises due to specific fears or triggers. Quetiapine also appears to be particularly useful for normalizing obsessions and compulsions, and improving low mood, irritability and aggressiveness. A greater understanding of the pharmacology of drug alternatives and the neurobiology of psychiatric disorders is required to permit a more personalized medicine approach.

Propionic acidemia associated with visual hallucinations

Propionic acidemia, an autosomal recessive disorder, is a common form of organic aciduria resulting from the deficiency of propionyl-CoA carboxylase. It is characterized by frequent and potentially lethal episodes of metabolic acidosis often accompanied by hyperammonemia. A wide range of brain abnormalities have been reported in propionic acidemia. We report recurrent visual hallucinations in 2 children with propionic acidemia. Four visual hallucination events were observed in the 2 patients. Three episodes were preceded by an intercurrent illness, and 2 were associated with mild metabolic decompensation. The 2 events in one patient were associated with a seizure disorder with abnormal electroencephalogram. Brain magnetic resonance imaging showed abnormal basal ganglia and faint temporo-occipital swelling bilaterally. This is probably the first report of visual hallucinations in propionic acidemia and should alert the treating clinicians to look for visual hallucinations in patients with organic acidurias, especially in an unusually anxious child.

Factors associated with complex visual hallucinations during antidepressant treatment

Published case reports on complex visual hallucinations (CVH) occurring during antidepressant (AD) treatment were reviewed. Thirteen cases of CVH associated with SSRI treatment, 16 cases during tricyclic drug treatment and seven cases with other AD drug treatments were found. Nine patients were taking concomitant drugs while on therapy with SSRIs and four had a neurological disease in addition to depression. The cholinergic impoverishment occurring in dementia states or during concomitant therapy with anticholinergic drugs could increase the sensitivity to serotonergic agonists, triggering the manifestation of CVH. During tricyclic drug treatment, half of the reports were of hypnopompic or hypnagogic hallucinations and this can be associated with the effects of tricyclics (TCA) on sleep architecture. It is likely that the potent anticholinergic effect of amitriptyline was potentiated in a situation of a rapidly changing state of consciousness. In general, the review supports the view that an imbalance between serotonin and acetylcholine systems is at the root of AD-induced CVH, with a profile defined by a cholinergic hypoactivity and a serotonergic hyperactivity. Caution is needed when administering a combination of serotonergic and anticholinergic AD in the treatment of the demented population and in other already compromised patients because there is a risk of precipitating CVH.