Personality change in
(Note: this essay is concerned with the general widespread personality
change which may occur independently of the anatomical site of
the lesions. The lesions themselves may cause character change
very specific to the person with the disease. This essay does
not treat with this.)
Stereotypic changes in personality in people with aggressive
MS have long been recognized. Sometimes these personality changes
continue within remissions; this happened with Sarah: I recognised
that she was not herself even while she was able to walk for
miles. To look back at those times is not easy. I was aware that
I was looking at the very same mental state which I had seen
in others with MS. Here is an excellent paper which examines
this phenomenon, which is not accounted for by demyelination.
RHB et al., Personality Disorder in Multiple Sclerosis correlates
with cognitive impairment. J Neuropsychiatry Clin Neurosci 2001;
13: 70 - 76. Full pdf available link ] These authors come to the conclusion that this
personality change (which is, they say, characterised by elevated
neuroticism and reduction in empathy, agreeableness and conscientiousness)
is due to 'a neurogenic frontal lobe syndrome.' I think that
the word which best sums up the character-changes is insouciance:
a nonchalant lack of concern.
Not everyone with MS comes
to have this syndrome; it seems only to occur prior to and during
an actively progressive phase. It cannot be accounted for by
primary autoimmune myelinopathy. I believe it likely to be a
toxic state due to bacterial metabolites; there is some indirect
evidence for this. Let's look at this more deeply.
Our cells live in a fairly rigorously controlled milieu, a world
where homeostasis is important. Our cells are therefore very
careful as to what they allow out into the extracellular fluid.
Sometimes in disease this concern breaks down: in liver failure,
volatiles are released into the general circulation (they can
be smelled on the breath - the so-called fetor hepaticus.)
When they reach the brain they cause symptoms of hepatic encephalopathy.
This has an insidious onset, with cognitive impairment and a
reversal of day/night sleep rhythms. Spatial awareness is compromised.
Unlike our cells, bacteria do not generally live in a homeostatic
environment: they may even find an evolutionary advantage in
pumping toxic compounds into their environment. The student of
bacteriology quickly recognises the unique smell which many bacterial
species or genera possess. These smells are due to volatile organic
Volatile toxins tend to affect the higher centres which form
the personality first; think of alcohol and anaesthetic agents.
Interestingly, a minority of people with MS personality change
become disinhibited and take risks. As with intoxication with
volatiles, personality changes in MS are marked by a profound
elongation of reaction times.
Finally, there is the effect of antibiotics. Sarah had very aggressive
disease, and had lost insight into it. On starting doxycycline
she became delirious for some five days. Then she began to lose
that MS personality change. I began to see something of her old
self. It was like seeing someone leaving a prison cell.
I have to say that, in my experience, those who comply with treatment
rapidly lose this strange mental state. Indeed, those who retain
it are generally found, on close questioning, to have abandoned
treatment. And that's the rub. Some people don't like losing
the feeling of euphoria where their disabilities don't really
matter and where the future is unimportant. The cold light of
reality can be too much to bear. It is possible to conjecture
that a state of addiction may occur, from which withdrawal may
be painful. That is why a diligent and attentive carer is so
important. The antibiotics must be seen to be swallowed.
Indeed, recent research shows
that specific volatiles (tentatively hexanal and 5-methyl undecane)
are found in the breath of persons with MS [Ionescu R et al. Detection of multiple
sclerosis from exhaled breath using bilayers of polycyclic aromatic
hydrocarbons and single-wall carbon nanotubes. ACS Chem Neurosci.
2011 Dec 21;2(12):687-93. Epub 2011 Sep 22.] Hexanal (hexanaldehyde) is a molecule associated
with lipid peroxidation and is found in rancid foodstuffs.
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