RT Book, Section
A1 Hasbun, Rodrigo
A2 Schmidt, Gregory A.
A2 Kress, John P.
A2 Douglas, Ivor S.
SR Print(0)
ID 1201805936
T1 Bacterial Infections of the Central Nervous System
T2 Hall, Schmidt and Wood’s Principles of Critical Care, 5<sup>th</sup> Edition
YR 2023
FD 2023
PB McGraw Hill
PP New York, NY
SN 9781264264353
LK accessmedicine.mhmedical.com/content.aspx?aid=1201805936
RD 2024/09/14
AB KEY  POINTSAdults  with  bacterial  meningitis  usually  present  clinically  with  fever,  headache,  meningismus,  and/or  signs  of  cerebral  dysfunction;  elderly  patients,  however,  may  present  with  insidious  disease  manifested  only  by  lethargy  or  obtundation,  variable  signs  of  meningeal  irritation,  and  no  fever.Occasionally,  a  patient  with  acute  bacterial  meningitis  has  a  low  cerebrospinal  fluid  (CSF)  white  cell  count  despite  high  bacterial  concentrations  in  CSF;  therefore,  a  Gram  stain  and  culture  should  be  performed  on  every  CSF  specimen,  even  if  the  cell  count  is  normal.Neuroimaging  techniques  have  little  role  in  the  diagnosis  of  acute  bacterial  meningitis.  However,  computed  tomography  (CT)  should  be  performed  before  lumbar  puncture  when  a  space-occupying  lesion  of  the  central  nervous  system  (CNS)  is  suspected.  Clinical  features  for  which  patients  should  undergo  CT  scanning  prior  to  lumbar  puncture  are  altered  mental  status,  immunocompromise,  a  history  of  CNS  disease,  a  history  of  seizure  within  1  week  before  presentation,  papilledema,  and  focal  neurologic  abnormalities.Empirical  antimicrobial  therapy,  based  on  the  patient’s  age  and  underlying  disease  status,  should  be  initiated  as  soon  as  possible  in  patients  with  presumed  bacterial  meningitis;  therapy  should  never  be  delayed  while  diagnostic  tests  such  as  CT  are  awaited.Adjunctive  dexamethasone  therapy  has  been  shown  to  decrease  the  morbidity  rate  in  infants  and  children  with  acute  Haemophilus  influenzae  type  b  meningitis  and,  if  commenced  with  or  before  antimicrobial  therapy,  may  also  be  beneficial  for  pneumococcal  meningitis  in  childhood.  Adjunctive  dexamethasone  is  also  associated  with  decreased  morbidity  and  mortality  rates  in  adults  in  high-income  countries  with  pneumococcal  meningitis  when  administered  before  the  first  dose  of  antimicrobial  therapy.  Adjunctive  dexamethasone  is  associated  with  higher  mortality  in  Listeria  monocytogenes  meningitis.Fewer  than  50%  of  patients  with  brain  abscess  present  with  the  classic  triad  of  fever,  headache,  and  focal  neurologic  deficit;  the  clinical  presentation  of  brain  abscess  in  immunosuppressed  patients  may  be  masked  by  the  diminished  inflammatory  response.The  diagnosis  of  brain  abscess  has  been  revolutionized  by  the  development  of  CT;  magnetic  resonance  imaging  (MRI)  offers  advantages  over  CT  in  the  early  detection  of  cerebritis,  cerebral  edema,  and  satellite  lesions.  Restricted  diffusion  inside  the  ring-enhancing  lesion  differentiates  a  brain  abscess  from  malignancy  on  diffusion-weighted  imaging  (DWI).Aspiration  of  brain  abscess  under  stereotaxic  CT  guidance  is  useful  for  microbiologic  diagnosis,  drainage,  and  relief  of  increased  intracranial  pressure.A  short  course  of  corticosteroids  should  be  restricted  to  patients  with  brain  abscess  with  brain  edema  with  deteriorating  neurologic  status  and  increased  intracranial  pressure.Cranial  subdural  empyema  should  be  suspected  in  patients  with  headache,  vomiting,  fever,  change  in  mental  status,  and  rapid  progression  of  focal  neurologic  signs.Spinal  epidural  abscess  may  develop  acutely  or  chronically,  with  symptoms  and  signs  of  focal  vertebral  pain,  nerve  root  pain,  motor  or  sensory  defects,  and  paralysis;  the  transition  to  paralysis  may  be  rapid,  indicating  the  need  for  emergent  neurosurgical  evaluation,  diagnosis,  and  treatment.Emergent  neurosurgical  therapy  is  essential  for  the  management  of  subdural  empyema  because  antibiotics  do  not  reliably  sterilize  these  lesions.Rapid  surgical  decompression  should  be  performed  in  patients  with  spinal  epidural  abscess  who  have  increasing  neurologic  deficit,  persistent  severe  pain,  or  increasing  temperature  or  peripheral  white  blood  cell  count.Lateral  gaze  palsy  may  be  ...