Hallucinations

Hallucinations have several important qualities which are essential in differentiating from
other mental phenomena:
1. They take place at the same time as other sensory perceptions – e.g. the voice is
heard even when music is playing or someone is talking to me. So they are
different from dreams where no real component exists alongside the false
perception.
2. They take place in the same space as other perceptions - angel is seen standing at the
corner of my room. This is different from fantasy or imagery which takes place in
a subjective space.
3. They are experienced as sensations – not as thoughts – contrast from obsessional
images.
4. The percept has all qualities of an object – i.e. it is believed that it can be experienced
in other modalities too, like a real object which can be seen, felt, smelt and heard.
This is why hallucinators search for the man behind the voice, or try and reach out
and touch visual percepts.
5. They are involuntary – appearance cannot be controlled; independent – will exist
even when not perceived by the hallucinators; may lack quality of publicness – not
every one could hear and see them.
Auditory Hallucinations:
 Elementary, unstructured hallucinations are seen in acute organic states.


 Musical hallucinations are similar to Charles Bonnet syndrome in visual
domain – can occur in those with deafness, also in organic conditions. Formed
auditions like voices – as in thought echo – cannot be elementary.
 Phonemes are any auditory hallucinations that occur as human voices.
Schizophrenic phonemes are usually multiple, may or may not be recognizable,
usually male with a different accent, speaking in one’s mother tongue and
usually episodic - almost never continuous. When a same word is repeated
continuously, normal subjects hear phonetically linked but different words.
Hallucinating schizophrenia subjects hear different words that have no phonetic
connection to the original repeated word – this is called verbal transformation
effect. Patients could be distracted from their voices; but it is the attention paid to
external stimulus which is more important than the degree of external stimulus
used to distract.
 Alcoholic hallucinosis initially starts as fragmented voices, later organised into
clear voices.
Visual hallucinations:
 Occipital lobe tumours, post concussional states, epileptic twilight state, hepatic
failure (any toxic delirium), dementia are some causes for visual hallucinations.
 30% of old age psychiatric referrals have visual hallucinations.
 Solvent sniffing and hallucinogens can cause elementary visual hallucinations like
light-flashes.
 Simultaneous visual verbal hallucinations – green man speaking to me – is seen in
TLE.
 Visual hallucinations are very uncommon in schizophrenia (But Andreasen quotes
30% in a series observed with acute schizophrenia).
 Reports of “black patch” psychosis were frequent following simultaneous bilateral
cataract surgery in the early era of the procedure, attributed to sensory
deprivation, leading to the recommendation that only one eye be operated on at a
time. It was subsequently recognized that “black patch” psychosis was a relatively
uncommon postoperative delirium partly due to anticholinergic eye drops3
Charles Bonnet Syndrome:
 Elderly patients, with normal consciousness and no brain pathology, with
reduced visual acuity due to ocular problems, experience vivid, distinct,
usually well-coloured (in contrast to real sensation that is blurred due to eye
disease) formed hallucinations – mostly humans, at times animals and cartoons.
 These objects usually show movement, and can be voluntarily controlled –
disappear on closing the eyes; insight about unreality is usually preserved –
though they may evoke emotions including fear and joy.

 About 1/3rd are elementary; usually the hallucinations are located in external
space.
 Podoll's criteria for diagnosis include: Elderly person with normal
consciousness with visual hallucinations; not in the presence of delirium,
dementia, psychosis, intoxication or neurological disorder with lesions of
central visual cortex; Reduced vision resulting from eye disease (most
commonly macular degeneration). The syndrome can occur in people with
normal vision45
Lilliputian hallucinations can occur in visual or haptic mode – they usually involve
seeing tiny people or animals (or feeling diminutive insects crawling if haptic)
and are seen in delirium tremens and unlike other organic visual hallucinations,
Lilliputian hallucinations can be accompanied by pleasure though often
intermingled with terror. These are not the same as micropsia. Patients with DT
often have prodromal affect or pareidolic illusions before these hallucinations.
Autoscopic hallucinations (Fere 1891) are the visual experience of seeing oneself.
Males predominate 2:1, impaired consciousness is a common accompaniment
and depression is the commonest psychiatric cause. They are also called phantom
mirror images and may take the form of pseudohallucinations. Schizophrenia
(usually pseudo), TLE, parietal lesions (organic states more likely to have true
hallucinations) are also implicated. In negative autoscopy one looks into a mirror
and sees no image at all.
Palinopsia: palin for "again" and opsia for "seeing". It is a visual disturbance that causes
images to persist even after their corresponding stimulus has left. It is seen in
LSD use, migraine, occipital epilepsy, head trauma. It is similar to afterimage but
colour inversion (usually shadows or distorted colours noted in afterimages) is
conspicuously absent.
Somatic hallucinations:
These can be divided into superficial, visceral and kinaesthetic.
The superficial somatic hallucinations are tactile (haptic - touch), hygric (fluid –
wetness etc) and thermic (heat or cold).
Visceral hallucinations are usually pain like sensations arising from deep viscera like
liver.
Kinaesthetic or proprioceptive hallucinations refer to joint or muscle sense, often
linked to bizarre somatic delusions. They are also seen in benzodiazepine
withdrawal and alcohol intoxication.
Formication (formic acid – from ant) is a special type of haptic hallucination –
unpleasant sensation of little animals or insects crawling under skin, seen in DT
and cocaine intoxication.

Tactile hallucinations can be seen in parietal seizures. Superficial somatic
hallucinations are almost never noted in TLE, though visceral sense of ‘raising
epigastrium’ is seen.
The common experience of phantom limb is a body image disturbance and not a
hallucination; though it is in external space, it does not satisfy other qualities of
hallucination and patients are aware of unreality usually. It is a body image
disturbance with neurological basis.
Somatic hallucinations may or may not be accompanied by passivity delusions.
Without the passivity delusions they cannot be classed as a First rank symptom.
Olfactory hallucinations can occur in aura of TLE – usually burning smell or urine smell.
In depression this can be an adjunct to nihilism.
Gustatory hallucinations e.g. bitter taste of poison can give rise to delusions of
persecution in schizophrenia. They are also seen in TLE.
Extracampine hallucinations: Hallucinations that occur outside the normal field of
perception e.g. images seen behind your back, under your sternum or hearing voices from
Inverness etc. They occur in schizophrenia, epilepsy and also in hypnagogic
hallucinations of healthy people – so not diagnostically important.
Both illusions and hallucinations are not necessarily pathological though they both are
false perceptions, along with pseudohallucinations. For example hypnagogic
hallucinations (hallucinations when going to sleep – go for gogic - usually auditory. Also
seen in Narcolepsy-cataplexy. They can be visual or tactile too. First noted by Aristotle)
and hypnopompic hallucinations (hallucinations when waking up) can occur in normal
individuals. They also occur in glue sniffing, post infective depression, children with
fevers and in phobic anxiety. Also sensory deprivation in normal healthy people can
produce hallucinations. They are not more frequent in schizophrenia than other
conditions.
Functional hallucinations: An external stimulus provokes hallucination, and both
hallucination and stimulus are in same modality but individually perceived. E.g. voices
heard whenever the noise of water running through tap is heard. They are not illusions –
as the stimulus is perceived appropriately (noise of water), but in addition there is
another perception (voices) without any appropriate object.
Synaesthesia:
The phenomenon of perceiving a stimulus of one modality in a different modality
(may be single or multiple modalities) is called synaesthesia. E.g. tasting the
music, hearing colours and smelling voices.
It is not a hallucination as the perceived object has an appropriate stimulus. The
original stimulus is usually perceived in appropriate modality too when the cross
modality perception occurs (syn – joint, simultaneous).
It is common in females’ 4:1, runs in families and colour-number synaesthesia is the
most common form.
It is thought to be due to extensive cross-wiring between multimodal association
regions in some people, probably due to failed selective pruning.
Reflex hallucinations:
These are hallucinations in one modality provoked reflexly by stimulus in another
modality. E.g. seeing an angel whenever listening to music.
They are similar to functional hallucinations in that there is a stimulus, which is
perceived normally, followed by a hallucinatory perception – only difference
being the modality of stimulus and perception being same in functional while
different in reflex hallucinations.
It is important to differentiate synaesthesia from reflex hallucinations in EMIs.
In synaesthesia it is the music that is seen – the stimulus and object of perception remain
the same albeit in different modalities - the patient does not claim that she could
see Jesus or angel.
Also the perceptions are simple, unformed and non-bizarre in synaesthesia e.g. colours;
in reflex hallucination these are formed voices, vivid images like angels etc.
The stimulus –perception sequence is usually completed before hallucination occurs in
reflex hallucination – ‘I heard the music and then came the angel’; in synaesthesia
music itself is seen as colour – the experiences are simultaneous.

Pseudohallucinations

There are two different definitions: Involuntary hallucination-like experiences
occurring in inner subjective space, with vivid outline that are absolutely
different from normal sense perceptions and hallucinations (Kandinsky, Jaspers
& Sims). Hallucinations that are recognised to be unreal and self-originating are
pseudohallucinations according to Hare. The former definition is used more
often by European psychopathologists.
Pseudohallucinations are not pathognomonic of anything; they are not necessarily
psychopathological too – so need to be differentiated from hallucinations.
They are intermediate between fantasy (imagery) and hallucinations;
Like fantasy they are in subjective space, lack quality of concrete reality, have quality
of idea and so not sought in other modalities simultaneously (not searched for,
no attempts to reach out etc) and appreciated to be observer dependent, self
originating.
Like a hallucination, they have clear outline, vivid, retained for good length of time,
cannot be dismissed at will and are behaviourally and emotionally relevant i.e.
acted upon or felt for.
The hallucinatory experiences of bereavement and in Ganser’s state are
pseudohallucinations.

Tourette’s syndrome

A detailed symptom analysis using principal component analysis technique (factor analysis) of 410 TS patients revealed five groups of symptoms. These five factors accounted for 46.6% of the symptomatic variance in the sample.

Factor (1) socially inappropriate behaviours and other complex vocal tics; - includes coprolalia, copropraxia, echolalia, echopraxia, palilalia, palipraxia, hitting, spitting, kicking, random words, forced touching and self-injurious behaviour.

Factor (2) complex motor tics;(e.g. arm, leg, foot movements, hopping, skipping, jumping and torso movements).

Factor (3) simple tics; - includes coughing, tensing of the body, grunting and simple motor and vocal/phonic tics (e.g. eye blinking, facial tics, head tics, noises, and throat clearing).

Factor (4) compulsive behaviours such as such as repetitive looking, adjusting clothing, finger tapping, leg and foot movement, and tensing of the abdomen.

and

Factor (5) simple motor and vocal/phonic tics and touching oneself.

Glossolalia refers to production of unintelligible utterances, often in a religious disoociative state. ('speaking in tongues') This is not a feature of TS.

How Alzheimer's infects the brain

A scientific breakthrough in the understanding of how Alzheimer's disease may spread across the brain of elderly patients might lead to novel ways of treating senile dementia, scientists have announced.
A study has discovered that a key brain protein linked with Alzheimer's disease has infectious properties that allow defects in the protein to be transmitted through the brain and so leads to debilitating neuro-degeneration.
It is the first time that scientists have detected infectious properties in the so-called tau protein which causes aggregates of particles known as "neurofibrillary tangles" to build up inside the brain cells of Alzheimer's patients. The tangles lead to the disease's symptoms.

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undo gmail messages

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