Toxins and Infections

Question 1

Herpes Simplex Encephalitis

Answer 1

Severe loss of brain tissue in the medial temporal lobe (preference for limbic system). Results in severe anterograde amnesia, social deficits and personality change.

Question 2

Chronic Fatigue Syndrome

Answer 2

Symptoms of fatigue that persists over 6 months with no identifiable cause. Results in poor concentration and attention and slowed information processing.

Question 3

Cannabis

Answer 3

Causes hallucinations, emotional reactivity, disorientation and memory loss (acute). Long term use can result in affective blunting, apathy, restlessness, confusion and poor recent memory.

Question 4

Cocaine

Answer 4

Causes increased arousal and confidence, but also agitation, paranoia, delusions, hallucinations and panic attacks (acute). Long term use can result in brain damage due to seizures, haemorrhagic strokes, cardiac/respiratory failure and deficits to processing speed, memory and mental flexibility.

Question 5

Opiates (Heroin/Morphine)

Answer 5

Less severe cognitive deficits, but more addictive. Can cause impaired visuospatial functioning, however this is likely to be due to the other substances heroin tends to be mixed with.

Question 6

Methamphetamine (Speed)

Answer 6

Increases blood pressure and weakens blood vessel walls, increasing the risk of haemorrhagic stroke. Long term use is associated with hallucinations, psychotic episodes and vulnerability to further psychosis.

Question 7

MPTP (Synthetic Heroin)

Answer 7

Same effects as heroin but also affects dopaminergic neurons in the substantia nigra. Three phases that can result from the first use: acute (resting tremor, disorientation, blurred vision) subacute (rigidity, inability to move) and chronic (if first two phases don’t resolve, Parkinson’s type syndrome develops).

Question 8

MDMA (Ecstasy)

Answer 8

Causes confusion, depression, anxiety, paranoia, sleeplessness, muscle tension, tremors, high blood pressure, dehydration and possible death. Long term use can result in confusion, depression, executive function impairment and working memory problems.

Question 9

Solvents

Answer 9

Have a preference for fat rich tissue (i.e. myelin) and can lead to stroke, slowed response speed, attention and concentration deficits and movement disorders.

Question 10

Pesticides

Answer 10

Designed to destroy nerve bundles. Severe acute exposure can result in coma, convulsions and death.

Question 11

Lead

Answer 11

Long term exposure can result in deficits to memory, learning, processing speed and coordination.

Question 12

Mercury

Answer 12

A single high dose can cause sensory, motor or cognitive deficits or death. Low level exposure causes deficits to attention, memory, reasoning and visuomotor coordination.

Question 13

Manganese

Answer 13

Acute high doses or chronic low doses can result in Parkinson’s like symptoms, slowed mental processing and impaired visuoperceptual accuracy.

Question 14

Gliomas

Answer 14

Tumours that arise from glial cells. Usually deep within the brain and difficult to treat. Symptoms are caused by the tumour infiltrating surrounding cells.

Question 15

Meningiomas

Answer 15

Tumours that occur in the meninges of the brain. Symptoms are caused by the growth compressing underlying tissue.

Question 16

CNS Lymphoma

Answer 16

Single or multiple lesions clustering around the ventricles. Difficult to treat (usually terminal).