Course  and  Sequela. — Delirium  tremens  lasts  from  three  to  seven  days,
and  commonly  terminates  in  recovery.  Death  occurs  chiefly  in  those  who
have  had  several  previous  attacks,  or  whose  tissues  are  gravely  damaged,
either  by  the  influence  of  long-continued  intemperance  or  by  senile  degen-
eration. Its  common  causes  are  exhaustion  and  gradual  failure  of  the  heart's
action.  Sometimes  death  occurs  suddenly,  from  unexpected  syncope.  Death
may  also  result  from  associated  acute  diseases,  especially  from  pneumonia.
The  mortality  has  been  variously  stated;  v.  Franque's  estimate  of  18  per
cent,  is  probably  near  the  truth.*

Most  patients  who  recover  do  so  perfectly.  Sometimes,  however,  the
mental  state  continues  abnormal.  The  sleep  that  brings  physical  quietude
may  only  partially  restore  the  mental  balance.  The  distressing  hallucina-
tions cease,  but  some  more  stable  delusion  remains,  and  may  last  for  weeks
or  months.  If  the  patient  has  had  a  previous  attack  with  this  sequel,  the
duration  of  the  mental  change  is  longer,  and  the  state  may  even  be  perma-
nent. In  that  event  there  is  usually  progressive  failure  of  memory  and  of
mental  power,  so  that  the  patient  passes  into  a  condition  of  chronic  insanity
or  of  chronic  dementia.  This  persistence  of  mental  change  is  met  with
chiefly  in  those  who  inherit  a  tendency  to  insanity,  and  the  stronger  this  is,
the  greater  is  the  tendency  to  this  sequel,  and  the  more  readily  does  it  occur.
*  This  estimate  was  calculated  from  21 17  cases  (v.  Franque, "  Ueber  Delirium  Tremens,"

Munich,  1859).
ACUTE   ALCOHOLISM.  1283

Pathology. — In  a  case  of  pure  alcoholic  delirium,  the  pathological  changes
are  slight,  and  consist  only  in  signs  of  congestion  of  the  cortex  of  the  brain
and  sometimes  of  other  parts,  especially  of  the  medulla  and  spinal  cord.
