1. Headache and Inability to Solve Quadratic Equations
Jonathan A. Edlow, MD, FACEP
Associate Chief, Department of Emergency Medicine
Beth Israel Deaconess Medical Center
Assistant Professor of Medicine
Harvard Medical School
Boston, MA

2. History 32 yo male with headache for 3 weeks.
A mathematics grad student at MIT, he has noticed increasing problems at work, such as his ability to solve complex differential calculus problems and quadratic equations
Both the HA and the math difficulty have increased gradually over the 3 weeks

3. History of Present Illness
Severity: gradually progressing to 7/10
Quality: waxing, waning, pressure-like, unfamiliar (he rarely gets HA)
Onset: gradual
Location: left sided front-parietal, non-radiating

4. History of Present Illness
ROS and associated symptoms:
+ nausea & vomiting (once, yesterday)
- fever, photophobia, neck pain, visual changes, focal weakness or sensory changes. No ear or sinus pain, respiratory or GI symptoms
No head trauma

5. Past History, Meds, Allergies
Asthma (mild, never hospitalized)
No allergies
No medications except for Tylenol which he has been taking for the present HA, and which helped “about 66.67%”

6. Social History
He is at the point of defending his PhD thesis and has been having problems with his advisor
Non-smoker
Drinks socially
He is homosexual, monogamous for 4 years. He has been HIV tested 1 years ago and was negative

7. Physical Examination Alert, oriented, looks well Vital signs:
Temp: 99.4
P: 72 BP: 128/72 R: 14
General physical exam, including a careful HEENT exam, is entirely normal; neck is supple
No rash, lymphadenopathy or murmur

8. Neurological Examination
MS normal (I was unable to test his math abilities)
CN 2-12 normal, including good venous pulsations
Motor: 5/5 strength with no pronator drift
Sensory, gait and cerebellar all normal
Reflexes: normal, toes down-going

9. Venous Pulsations

10. Differential Diagnosis
Tension HA
Migraine HA
Sinusitis-related HA
SAH
Meningitis
Mass lesion
Hematoma (SDH, EDH, parenchymal)
Tumor
Infection (brain abscess, subdural empyema)

11. ED Work Up
Treat him with analgesics and discharge him with follow-up with his PCP in 2-3 days?
Send a ESR and WBC count?
Perform a spinal tap?
Order a brain CT scan?

14. Ring Enhancing Lesion: Differential Diagnosis
Bacterial brain abscess
Toxoplasmosis, cryptococcosis
Tumor (glioblastoma or metastatic)
Lymphoma
Infarction
Necrotizing encephalitis
Granuloma

15. Toxoplasmosis
Glioblastoma vs. lymphoma

16. Key Teaching Points
Work-up patients with new, unusual HA, esp. if severe and/or abrupt in onset. Is there another likely diagnosis?
Patients with brain abscess often have no fever nor  WBC count
Patients with frontal lobe processes often have normal exams
The likely organisms and location asst. with brain abscess are a function of the underlying pathophysiology
Bacterial brain abscess is a neurosurgical disease, although some may be cured with needle aspiration and IV antibiotics

17. Brain Abscess - Pathophysiology
Extension from contiguous infection (direct or via emissary veins)
Paranasal sinus: frontal lobe
Otogenic infection: temporal lobe
Hematogenous dissemination
Often multiple abscesses (often MCA territory)
Penetrating trauma and surgery
Depends on location of trauma/surgery
In 20-30%, no reason is identified (cryptogenic)

18. Emissary Veins Emissary veins
ddddddddddddddddddddddddddddddddddddddddddddddddd
dddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddd
Emissary veins

19. Proximity of Sinuses to Brain

20. Brain Abscess: Stages of Development
Early cerebritis (1-3 days)
Late cerebritis (4-9 days)
Early capsule (10-14 days)
Late capsule (beyond 14 days)

21. Early cerebritis
Early abscess

22. 8-days later: frank abscess in the same area
Left temporal cerebritis in a diabetic patient with a facial infection

23. Brain Abscess: Clinical Presentation
Quite variable, HA being the most common (~ 80-90%)
Seizure (~ 50%)
Fever < 50% in some series
Papilledema < 25%
Signs of
Mass (depends on location)
Increased ICP (n/v, MS)

24. Brain Abscess: Clinical Clues (source)
Look for signs and symptoms of
Chronic ear infection
Sinusitis
Odontogenic infection
Endocarditis (or bacteremia of any cause)
Lung abscess
Recent body piercing

25. More Clues HIV infection Other immune defects
History of cancer (especially lung, breast, melanoma)

26. Brain Abscess: Imaging
CT (with and without contrast)
MR (superior when available)

27. Brain Abscess – LP?
While the risk is quite low, transtentorial herniation may occur
More importantly, an LP in brain abscess rarely is diagnostically useful
Cultures are almost always negative
The CSF formula is non-specific
Pressure is usually elevated

28. Brain Abscess: Initial Steps
ABC’s (if applicable)
Blood cultures (usually negative)
IV antibiotics
Selected based on mechanism
May be delayed in well-appearing patients in consultation with surgeon
Consultation with neurosurgeon
Steroids (for symptomatic cerebral vasogenic edema)
Anticonvulsants (if patient has seized)

29. Source Location Microbes Therapy Sinuses Frontal Aerobic strep
Anaerobic strep
Hemophilus, bacteroides
Pen (or cefotaxime) + metronidazole
Otogenic
Temporal
Cerebellum
Strep, bacterioides
Enterobacteraceae Pseudomonas
Pen + ceftazidime + metronidazole
Metastatic
Multiple (usually MCA)
Depends on source
(IE, lung, abd, GU)
Naf + metronidazole + cefotaxime
Penet. trauma
Variable
Staph aureus, clostridia, Enterobacteraceae
Naf + cefotaxime
Post-op
Same as above + Staph epi
Vanc + ceftazidime

30. Brain Abscess: Treatment
IV antibiotics for long duration
Surgical drainage
In some early-diagnosed cases (in cerebritis stage), prolonged IV antibiotics may be curative
Follow imaging studies
Treat underlying disease if necessary

31. Brain Abscess: Disposition
Admit for further treatment
To neurosurgery
Consider transfer to a center that is able to perform stereotactic biopsy

32. Outcome of Case
Patient transferred to a center with neurosurgical expertise
Stereotactic needle drainage was done yielding pus that cultured out mixed bacterial flora
Open craniotomy was not needed
He received 6 weeks of IV penicillin and metronidazole; HIV testing was negative
He regained his ability to solve quadratic equations

33. Questions?