Meningitis

Robert is a 23 year old student who presents with a gradual onset of a generalized headache. The headache started yesterday at the back of his head and now has spread all over. The pain is a constant ache of 7/10 and has only lessened a bit in intensity with motrim. He has no associated nausea, vomiting, photophobia or visual disturbance. He has not taken his temperature but says he has had some chills and feels unwell. He has had occasional headaches in the past which he has put down to tension headaches but they have not been as bad as this headache. He has a recent history of an upper respiratory tract infection with rhinorrhea and mild sore throat but no ear pain. In the past he had an inguinal hernia repair as a baby but has no other relevant past medical history. He is on no prescribed medication and does not usually take over the counter medication. He is a postgraduate student and drinks 6-10 beers a week and is a non smoker. He has had 2 lifetime female sexual partners and is currently not sexually active.

Physical examination:

Patient looks his stated age and is in moderate distress.

Vital signs. Temp: 38.8C,

Pulse: 96

BP: 130/86

Resp rate: 18

Weight 165lbs.

Head, EENT. Mild rhinorrhea, otherwise normal.

Neck. Pain in neck with flexing chin to chest

Kernigs sign: negative

Brudzinskis sign: negative

Chest. Clear to auscultation and percussion.

Heart. Normal heart sounds with no added sounds.

Abdomen. Soft and non tender. Normal liver. Spleen not palpable. Normal bowel

sounds.

Neurological Orientated x3. Cranial nerves II-XII intact. Normal tone, power, sensation reflexes and cerebellar function.

Commentary:

This patient presents with what he describes as a worse than usual headache and systemic symptoms of possible fever and malaise. Any patient presenting with a worse than usual headache needs to be evaluated carefully to rule out life threatening causes of headache.(Table 1). Guidelines from the American college of emergency physicians state that neuro imaging needs to be considered for any patient presenting with an acute onset headache to evaluate for an intracranial hemorrhage 1. (Table 2).Generally the clinical history is not useful in diagnosing meningitis even the symptoms of generalized headache, neck pain, nausea and vomiting are not specific enough in establishing the diagnosis of meningitis. However the history of an ante-cedent febrile illness such as otitis media, pneumonia or an upper respiratory tract infection is not uncommon in meningitis.2 (Table 3).The clinical examination can be helpful. In a systematic review analyzing the sensitivity of the physical examination in the diagnosis of meningitis the two largest studies containing 398 patients reported that 99-100% of patients had at least one of neck stiffness, fever or change in mental status, which means meningitis can virtually be ruled out in a patient without any of these signs. 3

Signs of Meningeal Irritation

1. Neck stiffness: in multiple studies including 733 patients, neck stiffness had a pooled sensitivity of 70%.3

2. Kernigs and Brudzinskis signs: these have not been well studied. In Brudzinskis original paper of 42 cases of meningitis Kernigs sign had a sensitivity of 42% and Brudzinskis had a sensitivity of 97%. 4

3. Jolt accentuation of headache.

In the one small study describing this sign the sensitivity was 100% with a positive likelihood ratio of 2.2 and a negative likelihood ratio of 0. 5

Other signs and symptoms associated with meningitis.

  • Paralysis of the 4th, 5th , 6th and 7th cranial nerves can occur in 5-10% of adults with community acquired meningitis and papilledema occurs in 1%. (6)
  • A petechial or purpuric rash can occur in meningococcal meningitis.
  • Seizures may occur particularly in meningitis due to streptococci pnemoniae.

Causes of meningitis

The most common cause of meningitis is viral most often an enterovirus. Arboviruses, herpes viruses and HIV are other viral causes of meningitis. The term aseptic meningitis is used for meningitis not caused by a bacterial infection but would also include meningitis caused by chemicals and carcinomatosis. Viral meningitis usually causes symptoms less severe than those of bacterial meningitis but a definitive diagnosis can only be made after examination of the CSF

The most common causes of bacterial meningitis are Streptococcus pneumoniae and Neisseria meningitides which cause over 90% of bacterial meningitis in adults. Other bacterial causes are Listeria monocytogenes, E.Coli and Hemophilus influenzae. Bacterial meningitis is more severe than viral meningitis and can rapidly lead to death if not treated promptly. 6

Management

In this situation where the patient is febrile it would be reasonable to proceed with a lumbar puncture to evaluate the CSF for a cell count, protein and glucose measurement and gram stain and culture. If there was doubt about the diagnosis of meningitis vs. subarachnoid hemorrhage a CT scan would be indicated to look for evidence of raised intra cranial pressure prior to doing the lumbar puncture.

Summary

  1. In a patient without any of fever, neck stiffness and change in mental status the diagnosis of meningitis is highly unlikely.
  2. Fever is the most sensitive sign out of the above triad.
  3. The classic signs of Kernigs and Brudzinski have a low sensitivity but high specificity.
  4. Jolt accentuation of headache may be a useful additional sign of meningitis.

Table 1

References.

  1. Clinical policy: Critical issues in the evaluation and management of patients presenting to the emergency department with acute headache. Annals of Emerg Med. 2002 ;39 (1): 108-22.
  2. Goldman: Cecil textbook of Medicine 21st edition. Copyright 2000. W. B Saunders.
  3. Attia J, Hatala R, Cook DJ, Wong JG. Does the adult patient have meningitis? JAMA 1999;281:175-181.
  4. Brody IA, Wilkins RH. The signs of Kernig and Brudzinski. Aqrch Neurol.1969;21:215-218.
  5. Uchihara T, Tsukagoshi H. Jolt accentuation of headache: the most sensitive sign of pleocytosis. Headache.1991;31:167-171.
  6. Durand ML et al. Acute bacterial meningitis in adults-a review of 493 episodes. NEJM 1993;328(1):21-28.

April 2005p. 1Headache for Educators Project