5 -  Wernicke's encephalopathy in animals
Although the mammillary bodies are prominent sites
of damage in cases of human alcoholism and
thiamine deficiency, but this has not been a constant
finding in animal studies.  Evans et al. (1942)
reported on an epidemic disease that killed one-third
of the foxes at the Chastek fur farm in Minnesota.  
They named the disorder Chastek paralysis and
described it as an animal counterpart of Wernicke’s
encephalopathy.  The disease was traced to thiamine
deficiency in the diet of raw fish fed to the animals.

Bilaterally symmetric hemorrhages were found in the
brainstem of the foxes with Chastek paralysis.  As in
Wernicke’s patients paraventricular nuclei were
damaged.  Evans et al. noted lesions in the dorsal
nucleus of the vagus, the vestibular nuclei, the
inferior colliculi, the nucleus of the third cranial nerve,
and walls of the third ventricle, and additionally
lesions of the inferior olives and cerebellar folia close
the fourth ventricle.  Raw fish contains an enzyme
that inactivates thiamine.  In countries like Japan raw
fish in the diet may have compounded the problem of
thiamine deficiency of refined rice in cases of beriberi.

Jubb et al. (1956) investigated brain damage in pet
cats that were becoming ill and dying when, like the
Chastek foxes, fed a commercial cat food containing
whole fish.  They also reproduced the illness
experimentally.  In cats the most consistent and
severe damage was found in the inferior colliculi.  The
mammillary bodies were irregularly involved.  Jubb et
al. compared this bilaterally symmetric pattern of
damage to that seen in streptomycin poisoning, to
which cats are particularly susceptible.  This suggests
that species differences in vulnerability may be due to
differences in mitochondrial DNA.  Familial sensitivity
to streptomycin and other aminoglycoside antibiotics
has been discovered in humans.  Deafness is one of
the most serious consequences (Jacobs 1997,
Schapira 1998).

Rinehart et al. (1949) investigated brain damage in
monkeys maintained on a diet lacking thiamine.  They
found damage in the putamen and inferior colliculi,
but not in the mammillary bodies.  They provided a
table that shows species differences between man,
monkey, fox, rat, and pigeon.  Witt and Goldman-
Rakic (1983) also studied thiamine deficiency in
monkeys, and also found consistent damage in the
inferior colliculi but not the mammillary bodies.

Irle and Markowitsch (1983) investigated the effects in
laboratory rats of chronic alcohol consumption and
thiamine deprivation augmented with pyrithiamine
injections.  Pyrithiamine displaces thiamine at its sites
of activity on the enzyme molecules for which it is an
essential cofactor [9].  Irle and Markowitsch found the
most striking damage in the dentate gyrus of the
hippocampus, and also noted involvement of the
mammillary bodies, inferior colliculi, and dorsal vermis
of the cerebellum.  Witt (1985) reviewed the reports
of thiamine deprivation in animal studies but drew no
conclusion about the variability found in different
species.

In human cases, the inferior colliculi have been
observed to be the most severely damaged brain
nuclei under extreme conditions of thiamine
deficiency.  Vortmeyer et al. (1992) reported the
neuropathology found in three critically ill post-
surgical patients who were maintained for more than
three weeks on thiamine deficient parenteral feeding.  
The damage reported by Vortmeyer et al. was
hemorrhagic.  The inferior colliculi were severely
damaged in all three cases, while the mammillary
bodies were minimally affected in one case but not at
all in the other two.  Vortmeyer et al. suggested that
the mammillary bodies might be spared in hyperacute
cases of thiamine deficiency.

Once more, autoradiographic measures of blood flow
and glucose uptake would seem to explain the
difference in outcome between a gradual loss of
aerobic function and situations in which a
catastrophic event completely disables aerobic
metabolism.

Full References

References

1. Evans CA, Carlson WE, Green EG (1942) The pathology of Chastek paralysis in foxes. A
   counterpart of Wernicke's hemorrhagic polioencephalitis of man. American Journal of
   Pathology 18:79-90.
   
2. Carpenter KJ (2000) Beriberi, White Rice, and Vitamin B: A Disease, a Cause, and a Cure.
   Berkeley: University of California Press.
   
3. Jubb KV Saunders LZ, Coates HV (1956) Thiamine deficiency encephalopathy in cats. Journal
   of Comparative Pathology 66:217-227.
   
4. Jacobs HT (1997) Mitochondrial deafness. Annals of Medicine 29:483-491.
   
5. Schapira AH (1998) Inborn and induced defects of mitochondria. Arch Neurol 55:1293-1296.
   
6. Rinehart JF, Friedman M, Greenberg LD (1949) Effect of experimental thiamine deficiency on
   the nervous system of the rhesus monkey. Archives of Pathology 48:129-139.
   
7. Witt ED, Goldman-Rakic PS (1983) Intermittent thiamine deficiency in the rhesus monkey. I.
   Progression of neurological signs and neuroanatomical lesions. Annals of Neurology 13:376-
   395.
   
8. Irle E, Markowitsch HJ (1983) Widespread neuroanatomical damage and learning deficits
   following chronic alcohol consumption or vitamin B1 (thiamine) deficiency in rats. Behavioral
   Brain Research 9:277-284.
   
9. Troncoso JC, Johnston MV, Hess KM, Griffin JW, Price DL (1981) Model of Wernicke's
   encephalopathy. Archives Of Neurology 38:350-354.
   
10. Witt ED (1985) Neuroanatomical consequences of thiamine deficiency: a comparative
    analysis. Alcohol and Alcoholism 20:201-221.
    
11. Vortmeyer AO, Hagel C, Laas R (1992) Haemorrhagic thiamine deficient encephalopathy
    following prolonged parenteral nutrition. Journal of Neurology, Neurosurgery and Psychiatry 55:
    826-829.
    

top

1. Evans CA et al. (1942) The
   pathology of Chastek paralysis
   in foxes. A counterpart of
   Wernicke's hemorrhagic
   polioencephalitis of man.
   
2. Carpenter KJ (2000) Beriberi,
   White Rice, and Vitamin B: A
   Disease, a Cause, and a Cure.
   
3. Jubb KV et al. (1956) Thiamine
   deficiency encephalopathy in
   cats.
   
4. Jacobs HT (1997)
   Mitochondrial deafness.
   
5. Schapira AH (1998) Inborn and
   induced defects of
   mitochondria.
   
6. Rinehart JF et al. (1949) Effect
   of experimental thiamine
   deficiency on the nervous
   system of the rhesus monkey.
   
7. Witt ED, Goldman-Rakic PS
   (1983) Intermittent thiamine
   deficiency in the rhesus
   monkey. I. Progression of
   neurological signs and
   neuroanatomical lesions.
   
8. Irle E, Markowitsch HJ (1983)
   Widespread neuroanatomical
   damage and learning deficits
   following chronic alcohol
   consumption or vitamin B1
   (thiamine) deficiency in rats.
   
9. Troncoso JC et al. (1981)
   Model of Wernicke's
   encephalopathy.
   
10. Witt ED (1985)
    Neuroanatomical
    consequences of thiamine
    deficiency: a comparative
    analysis.
    
11. Vortmeyer AO et al. (1992)
    Haemorrhagic thiamine
    deficient encephalopathy
    following prolonged parenteral
    nutrition.