Intern Report 6.1

Case Presentation by Dr. Eric Malone

 

HISTORY OF PRESENT ILLNESS:

This previously healthy 41-year-old patient comes to the emergency department complaining primarily of the acute onset of a severe headache 48 hours prior to presentation.  He states that he was sitting at home when the headache began, and denies any associated physical exertion.  He describes the headache as a severe, throbbing pressure unilateral, left-sided, temporal, and without radiation.  He has an associated feeling of dizziness, but no loss of vision, and no weakness or parasthesias in his extremities. He has had headaches in the past, but states that this headache is different in quality and is more severe.  Associated with the headache are 3 episodes of nonbilious, nonbloody vomiting over the past 48 hours. He has had persistent associated nausea. He felt well enough to try to go to the casino earlier the day of presentation, but his headache returned, and became more severe, so he went home.

No fever, URI, CP, SOB or other symptoms.

He is accompanied by family members, who state that he is usually not one to complain about pain. They are concerned because he does not seem to be acting like himself. They describe him as sleepy, and seeming “out of it.”

Review of Systems: Negative except as per HPI

Past Medical History, Surgical History, Medications: None

Allergies: None

Social history: Occasional social alcohol use, occasional marijuana use. Denies tobacco and intravenous drug use.

Family History: Notable for a grandmother who passed away from an aneurysm.

Physical Examination:

Vital Signs: Blood pressure was 158/98, pulse was 66, respirations were 18, temperature was 36.0 by mouth and oxygen saturations were 100% on room air

General: Awake, alert, lying in bed in moderate distress.  The patient keeps his eyes closed and is complaining of pain. He is drowsy but easily arousable. He responds to questions, but slowly.. Well-developed, well-nourished.  Appears stated age.

HEENT: Normocephalic, atraumatic.  Pupils equal round and reactive to light, photophobia, but no papilledema.  Extraocular movements are intact. Neck is supple, without lymphadenopathy. Mucous membranes are moist. Posterior oropharynx is nonerythematous. No meningismus.

Cardiovascular: Heart is regular rate and rhythm.  There are no murmurs, rubs, or gallops.  Distal pulses are palpable in all 4 extremities.  There is no evidence of peripheral edema.

Respiratory: Respirations are nonlabored, CTAB

Gastrointestinal: Abdomen is soft, nontender, and nondistended.

Musculoskeletal: The patient has full range of motion in all four extremities. There is no swelling.

Skin: No rash. Skin is clean, dry, and intact.

Neurologic: Alert, and oriented x3.  Pupils are equal round and reactive to light.  Extraocular eye movements are intact.  Sensation is intact in the face.  Jaw clench strength is intact.  Smile is symmetric.  The palate and uvula elevate symmetrically.  Neck rotation and shoulder shrug strength is intact.  The tongue protrudes in midline.  Sensation is intact to light touch in all 4 extremities.  Strength is 5/5 in all 4 extremities.

IV access was established and the patient was provided 4mg morphine IV, 10mg metoclopramide, and a 1L 0.9% NaCl bolus.

APTT, PT, INR within normal limits

CT head without contrast was performed and was negative for any acute intracranial process.

Following an explanation of the risks and benefits of the procedure,lumbar puncture was performed. CSF was obtained on the first attempt without difficulty. The CSF returned – (See picture below). Glucose and Protein were within normal limits. Cell count performed on Tube #2 demonstrated a RBC count of 6020. RBC count in Tube #4 was 3440.

Questions:

1) Does the above picture CSF represent a traumatic spinal tap or significant finding?

a) Traumatic Tap

b) Significant CSF finding

c) Normal Tap

d) This is urine and not CSF

2) What percentage of patients presenting with Subarachnoid hemorrhage demonstrate no evidence of blood on initial head CT?

a) 10%

b) 20%

c) 50%

d) Percent will vary depending on length of time from onset of bleeding

3) Which of the following is the most sensitive for the presence of SAH on CSF analysis?

a) Xanthochromia

b) Visual inspection of CSF

c) A persistent RBC count from Tube #1 to Tube #4.

d) Opening pressure

4) How long must RBCs remain in the CSF before Xanthochromia can be detected?

a)  2 hours

b) 6 hours

c) 12 hours

d) 24 hours

 

Case Discussion & Answers

1) b

2) d

3) a

4) c

Given the history of severe headache, and the provided lumbar puncture results, this patient went on to have CT-angiography performed. This demonstrated a 6mm basilar artery tip aneurysm. The patient then underwent angiography which demonstrated a small, wide based, basilar artery aneurysm as well as a small posterior communicating artery aneurysm that was embolized uneventfully.

The patient was observed in the NICU for 24 hours after embolization and was then observed on the general neurology floor for a further 24 hours before being discharged home on 81mg aspirin and 5mg amlodipine.

Discusssion:

This patient originally presented with the acute onset of severe headache that was different in quality than previous headaches. On initial examination, he was drowsy and photophobic, but demonstrated no neurologic deficits. His family history was remarkable for a family member that had passed away from an aneurysmal bleed. Given the character of the headache, duration of symptoms, and the patient’s seemingly depressed mental status, the initial concern was for subarachnoid hemorrhage. Subarachnoid hemorrhage is a rare, life threatening cause of headache in the emergency department. Most (~75%) arise secondary to aneurysm rupture. The incidence of SAH in patients presenting to the ED has been reported as 1-4%.  Risk factors associated with development of SAH include hypertension, smoking, excessive alcohol consumption, and the use of sympathomimetic drugs. Incidence increases with age.

The classic clinical presentation of a new onset SAH would be the sudden onset of a severe headache that reaches maximal intensity within minutes—the so-called “thunderclap” headache. There is additional association with exertional activities and those which require a Valsalva maneuver. Of the patients who present to the ED with a thunderclap headache, between 11 and 25% will have SAH. Any headache that is different in quality from the patient’s usual headache should raise concern for SAH on the differential. All patients with SAH do not present with headache: alternate initial presentations would include altered mental status, photophobia, or persistent nausea/vomiting

It is well established that a patient presenting with severe, acute onset headache should undergo evaluation with Head CT. Head CT is highly sensitive for SAH within hours after presentation. If performed within the first 6 hours of symptom onset, CT is 100% sensitive for SAH. CSF is continually circulated with resulting breakdown and dilution of blood, so this sensitivity decreases to 98% at 12 hours from onset and further decreases to 93% at 24 hours. Thus, any patient presenting after 6 hours from the onset of headache will need lumbar puncture performed to rule out the presence of blood in the CSF. CT is preferred to MRI given the increased sensitivity of CT to detect acute blood.

There has been some suggestion that in a select group of neurologically intact patients with normal vital signs and no evidence of elevated intracranial pressure that an LP first strategy may consume fewer resources and, given clinicians tendency to eschew LP when initial Head CT returns normal, result in fewer missed diagnoses. However, no clinical trials have yet assessed this method.

Xanthochromia

There remains question as to the best method of distinguishing a traumatic lumbar puncture from CSF containing blood from a SAH. Analysis for xanthochromia—the yellowish discoloration of CSF that occurs with increasing catabolic products of hemoglobin—is one such method. By far the most common method of assessing for xanthochromia involves the comparison of a centrifuged tube of CSF against a similar volume of water, both held against a white background. Approximately 99% if US hospital laboratories use this method. The more accurate method involves the spectrophotometric measurement of centrifuged CSF. Particularly when spectrophotometric analysis is to be performed, the tubes of CSF should be taken immediately to the lab, and kept in darkness so as to not accelerate the process of bilirubin degradation.

A second method of distinguishing traumatic lumbar puncture from true SAH involves the comparison of RBC counts across tubes of CSF. In a traumatic tap, the RBC count will decrease across tubes and the RBC in the last tube will approach zero. However, it is essential to note that a simple decrease in RBC count does not imply traumatic tap, nor does the use of an arbitrary cutoff of 25% decreased from Tube #1 to Tube #4.

Initial ED treatment and management involves resuscitation and stabilization. Patients with a significantly depressed level of consciousness or those at risk for respiratory center compromise should be intubated and sedated. It is essential that blood pressure be carefully monitored with most suggesting a target systolic blood pressure of 160 mm Hg, maintained with a titratable IV infusion if necessary. Nimodipine is typically initiated soon after the diagnosis of SAH to decrease the risk of vasospam. Pain should be aggressively treated with opioids as needed for persistent headache.

Early consultation with a Neurosurgeon or Neuro-internventionalist is crucial as a means to ultimately treat a bleeding aneurysm. Treatments of choice would involve clipping or coil embolization. Final prognosis depends primarily on initial presentation. The Hunt and Hess scale provides a method for grading patients based on initial clinical picture. Those patients initially presenting with low Hunt and Hess scores (I and II) tend to do well. Those with high grades (IV and V) have a poor prognosis.

Clinical Pearl:

Any patient presenting after 6 hours from the onset of headache will need lumbar puncture performed to rule out the presence of blood in the CSF. CT is preferred to MRI given the increased sensitivity of CT to detect acute blood.

References:

  1. Rosen’s Emergency Medicine, seventh edition, 2010, pages  1360-1361, Marx
  2. Tintinalli’s Emergency Medicine, 7th Edition, 2011, pages  1118-1120, Tintinalli
  3. Aneurysmal Subarachnoid Hemorrhage: An Update for Emergency Physicians. Journal of Emergency Medicine. Journal of Emergency Medicine. Vol 34, 2008. Edlow et al.
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2 Responses

  1. 1. (most likely … I don’t think this question is fair as the literature is all over the place on this and I don’t know how you can say for sure. Rosen’s says comparing tube 1 to tube 4 is junk. I can find a few articles in the last 10 years that look at this but I can’t find any study that fully validates any certain percentage decrease of RBC’s that definitively defines traumatic tap or not – I’ve seen anywhere from 30 to 70% decrease being needed to call it a traumatic tap. This pt had a 40% decrease)

    2. – varies depending on time of onset

    3. – xanthochromia

    4. … I guess. Again I don’t like this question, I think it needs to be less vague. Articles have noted xanthochromia in is little as 4 hours, some possibly even 2 (needs validation, but who is to say it is not right?)!! The sensitivity increases to close to 100% (with spectroscopy) at 12 hours though so I guess that is what I’ll put. Also, Rosen’s says 12 hours to develop.

    • Good Points but it will come out later today when the answers and discussion are posted. Protests on answers in the words of my former boss “They are discussable but not negotiable”.!

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