Lumbar Puncture (LP) Results - Drawing Conclusions from the CSF

Dx	RBCs*	WBCs*	Glucose (mg/dL)	Protein (mg/dL)	Opening Pressure (cm H20)
Normal	<10	<5	~2/3 of serum	15 - 45	10 - 20
Bacterial Meningitis	+/-	↑	↓	↑	↑
Viral Meningitis	+/-	↑	+/-	↑ or +/-	↑ or +/-
Aseptic Meningitis	+/-	↑	+/-	↑ or +/-	+/-
SAH	↑	↑	+/-	↑	↑ or +/-
Guillain-Barre	+/-	+/-	↑ or +/-	↑↑	+/-
MS	+/-	↑ or +/-	+/-	+/-	+/-
Pseudotumor Cerebri	+/-	+/-	+/-	+/-	↑↑↑

*per cubic mm

SHELF / USMLE Step 2 Practice Questions > Internal Medicine > Neurology

SHELF / USMLE Step 2 Practice Questions > Internal Medicine > Neurology

92 Case based vignette style practice questions from the American College of Physicians (ACP) with answers & thorough explanations - DOWNLOAD the .pdf

Want more great practice questions for the Medicine Shelf Exam? Go with MKSAP for Students 3

hypoxic-ischemic coma prognosis

When you are on you're on your neurology clerkship (or ICU rotations) you will undoubtedly encounter many patients in post-stroke comas. A good physical/neuro exam can help a lot with ultimate prognosis. After 7 days prognosis is almost always apparent. Here is a validated method based on Based on Levy et al JAMA 1985, 253

GOOD = mod disability (independent w/ ADLs) or better
POOR = death, persistent coma until death, or persistent veg state.

< 3hrs

• GOOD (41% good, 41% bad)
• Eyes: Roving conjugate
• Motor: Posturing or better
• POOR (94% bad, 0% good)
• Eyes: Absent pupillary responses
• Motor: Posturing or worse
  

24 hrs.

• GOOD (63% good, 7% bad)
• Eyes: Open to noise / spontaneously
• Motor: Withdraw or better
• POOR (95% bad, 1% good)
• Eyes: Not roving conjugate
  
• Motor: Still posturing or worse

3 days

• GOOD (77% good, 8% bad)
• Eyes: Normal orienting movements
• Motor: Withdraw or better
• POOR (93% bad, 0% good)
• Motor: Still posturing or worse
  

7 days

• GOOD (72% good, 6% bad)
• Obeys commands
  
• POOR (100% bad, 0% good)
• Not obeying commands
• Eyes: Not roving or orienting, not opening spontaneously

Neurology Clerkship

Neurology is often a short rotations giving you little time to prepare for the shelf. Below are the bread and butter resources to get you through.

• Downloads & Online Neurology Links
• General downloads for the wards - see Clinical Downloads.
• Shelf exam content breakdown & sample questions from the NMBE.
  
• Neurology
  
• Mini-Mental Status Exam (.pdf)
  
• Neuroexam.com - The complete neuro exam with videos.
• Neuro-Logic Exam - Excellent overview of the comlete neuro exam with videos, examples of abnormals and quizzes with answer explanations, great Shelf exam prep.
  

• Neurology PDA programs
  
• take your pick from Skyscape's* neurology collection.
  
• See PDA essentials for programs you should have for every rotation.

• Books for the Shelf:
• Blueprints Neurology - Easy to read and concise, it covers the major topics on the exam.
• Neurology Recall - Especially helpful on the floor and on rounds.
• Clinical Neuroanatomy Made Ridiculously Simple - Great for getting a grip on the anatomy & blood supply distribution.

*Skyscape progams are availble as free trials, they can also be cracked giving you access to the full version. Use google to figure out how.

Med-Spot on Med-Source: Altered Mental Stauts

Med-Spot: ED evaluation of Altered Mental Status (the infamous ΔMS)

• Definitions
• Disorders of consciousness: processes that affect arousal functions (reticular activating system), content of consciousness functions (cortex), or combination of both functions.
• Dementia: content of consciousness dysfunction, usually insidious onset with gradual decline; alertness is preserved
• Delirium: acute onset of arousal system dysfunction (+ content of consciousness dysfunction); always has an organic cause!
• Coma: results from disruption of the reticular activating system and/or disruption of bilateral cortical hemispheres; unilateral hemispheric disease does not cause a comatose state.
• Mini-mental state exam (MMSE) has 5 elements: orientation, registration, attention & calculation, recall, and languageGlasgow coma scale (GCS) has 3 elements: eye opening, verbal response, motor response
• Differential diagnosis (AEIOU, TIPS) - to be totally honest, I don't find this mnemonic to be all that helpful, but I have heard it from multiple residents and attendings so I thought I'd pass it along.
  
• Alcohol (intoxication, withdrawal, Wernicke’s encephalopathy)
• Electrolytes (hypernatremia, hyponatrema, uremia, hypercalcemia), Endocrinopathy (addison’s crisis, thyroid storm, hypothyroidism, hyperglycemia, diabetic ketoacidosis), Encephalopathy (uremic, hepatic, hypertensive)
• Insulin (hyperglycemia, hypoglycemia), Infection (meningitis, sepsis, encephalitis)
• Oxygen (hypoxia, carbon monoxide), Opiates (heroin, narcotics)
• Uremia
• Trauma, Toxicology (poisons, medications), Temperature (hypothermia, hyperthermia)
• Inborn errors of metabolism
• Psychiatric, Post-ictal state
• Seizures, Stroke, Space-occupying lesion (intracranial)
• Approach to the altered patient
• History: usually obtained from paramedics, family members, friends, etc…
• Primary survey: the ABCDE approach is crucial when evaluating the altered patient
• Obtain vital signs and perform a complete exam
• Special patients:
• Agitated or uncooperative patients need to be restrained in order to proceed with the evaluation and to protect the staff.
• Elderly patients: consider medications, co-morbid conditions. Minor infections such as urinary tract infections or pneumonias may cause significant ΔMS in this population.
• Pediatric patients: consider child abuse, toxic ingestions.
  

Med-Spot on Med-Source: Migraines

Med-Spot 4.25.07

Migraines may not be all bad. A new study out indicates that women with a lifetime history of migraine have less cognitive decline over time than women without migraine. The source of the improved memory retention has not yet been elucidated. Hypotheses include a beneficial effect of anti-migraine medications, diet and or behavior changes.

Study participants were evaluated with the Mini-Mental State Examination (MMSE) first from 1993 - 1996 and again in 2004 - 2005. A total of 204 migraineurs and 1,244 nonmigraineurs participated. Those over 50 who had migraine with aura initially scored lower on tests of immediate and delayed memory, but their performance declined significantly less over time compared with that of the nonmigraineurs.

In a statement issued by the American Academy of Neurology, Kalaydjian said: "Some medications for migraine headaches, such as ibuprofen, which may have a protective effect on memory, may be partially responsible for our findings, but it's unlikely to explain this association given we adjusted for this possibility in our study and the medications showed no indication of a significant protective effect." Another factor that needs to be explored is the possibility that migraineurs may alter their diet or behavior in some way that might improve cognition. "For example, alternative treatment for migraine includes adequate sleep, as well as behavioral and relaxation techniques, and a reduction in caffeine," Kalaydjian pointed out. "Despite these theories, it seems more likely that there may be some underlying biological mechanism, such as changes in blood vessels or underlying differences in brain activity, which results in decreased cognitive decline over time," Kalaydjian concluded. "More research is needed to fully understand how migraine affects cognition."

References:
Kalaydjian, P. P. Zandi, K. L. Swartz, W. W. Eaton, and C. Lyketsos How migraines impact cognitive function: Findings from the Baltimore ECA Neurology 2007 68: 1417-1424.
Reuters Health

Brain and Behavior (Neurology, Neuroanatomy & Psychology)

Brain and Behavior crams a lot into one course. The neuroanatomy portion is the most difficult part if you haven't had it before, but just like with gross anatomy, the more times you see it the easier it gets. A decent understanding of the spinal tracts the cranial nerves will enhance your understanding of neurologic disease and help you our later on the wards.

• Brain & Behavior Downloads
• Neuroexam.com has short videos of each component of a complete neuro-exam.
• The Whole Brain Atlas - Harvard's MRI/PET image library of the brain.
• Neuroanatomy Atlas - Downstate's interactive brain slices.
  
• Neuro-ophthalmology - Animated lessons on the neurology of eye movements and pupillary disorders.
• Recommended Brain & Behavior Textbooks
  
• Neuroanatomy: An Atlas of Structures, Sections, and Systems (Haines) - Great brain slice images, weaker on the pathways.
• The Human Brain: in Photographs and Diagrams - Nice pathway images. The atlas counterpart to Nolte's text.
• The Human Brain: An Introduction to Its Functional Anatomy(Nolte) - A quality text to compliment an atlas.