Archive for the ‘Uncategorized’ Category

Distinguishing neuropathic pain from nocioceptive pain

January 23, 2014
This study quantifies the value of the history among 269 patients with chronic pain in three pain clinics.


  • Neither their survey nor any individual findings were strong enough to hang one’s hat on.
  • The most helpful finding when present was a sensation of brushing.
  • The most helpful finding when absent was numbness.


  • Patients: 196 patients in whom two physicians agreed on the basis of the pain. Excluded were 106 patients for whom the physicians agreed that the pain had a mixed basis or for whom the physicians did not agree whether the pain was neuropathic.
  • Gold standard: consensus assessment by two physicians of the basis of the pain.



Predictive value
(assuming equal pretest probabilities of neuropathic and nocioceptive pain)

Finding Sensitivity Specificity Positive predictive value Negative predictive value
DN4 7-item survey(score 4 or more)





Numbness sensation





Painful cold sensation





Brushing sensation






van Seventer R, Vos C, Giezeman M, Meerding WJ, Arnould B, Regnault A, van Eerd M, Martin C, & Huygen F (2013). Validation of the Dutch version of the DN4 diagnostic questionnaire for neuropathic pain. Pain practice : the official journal of World Institute of Pain, 13 (5), 390-8 PMID: 23113981


Physical examination for detection of anemia

September 23, 2012
Twelve primary health care providers in Bangladesh examined 452 pregnant women (198 had Hb < 10) for the presence or absence of pallor on nine different anatomical sites, viz. nail-beds, nail-bed blanching, palm, palmar creases, face, lips, tongue, oral mucosa and conjunctiva
Below is a table (larger version is here) of the standardized colors the researchers used and the distribution of results for the conjunctival color.

Two other studies on this topic, all with different results are PMID 2297289 and 20049324

Distribution of color of the everted lower eyelid.
1 2 3 4 5 6 7 8 9 10 11 12 13
Hb < 10 28% 42% 36%
Hb 10 – 12 19% 19% 40%
Hb > 12 10% 53% Not


Chowdhury ME, Chongsuvivatwong V, Geater AF, Akhter HH, & Winn T (2002). Taking a medical history and using a colour scale during clinical examination of pallor improves detection of anaemia. Tropical medicine & international health : TM & IH, 7 (2), 133-9 PMID: 11841703

Hoover’s sign for the diagnosis of functional weakness

March 29, 2012

In a study of 124 patients with suspected stroke who presented with leg weakness, clinical evaluation ultimately determined that in eight patients (6%) the weakness was functional.

For functional weakness:

Sensitivity Specificity Predictive values at prevalence of 6%
Positive Negative
Hoover’s sign* 63%
(95% CI: 24 to 91)
(95% CI: 97 to 100)
100% 3%
* “was considered positive when there was weakness of voluntary hip extension in the presence of normal involuntary hip extension during contralateral hip flexion against resistance”.
Of note, the abductor sign is an alternative test for functional weakness. (PMID: 14707320)


McWhirter L, Stone J, Sandercock P, & Whiteley W (2011). Hoover’s sign for the diagnosis of functional weakness: a prospective unblinded cohort study in patients with suspected stroke. Journal of psychosomatic research, 71 (6), 384-6 PMID: 22118379

A “mini” Mini-Mental State Examination

July 15, 2011

The authors propose a six item screener (SIS) that contains six items from the Mini-Mental State Examination (MMSE):

The examiner first asks the patient to remember three items: GRASS PAPER SHOE. The examiner could repeat the words 3 times as needed to help the patient.

  • Orientation to time
    1. Year
    2. Month
    3. Day of the week
  • Recall of three items (one point each)

Patients: The authors studied 371 patients in the emergency room after excluding 587 patients, mostly due to having received sedating medications.

Results: As compared to the full MMSE, the accuracy of the SIS was:

  • Sensitivity 74%
  • Specificity 77%


Carpenter CR, Despain B, Keeling TN, Shah M, & Rothenberger M (2011). The Six-Item Screener and AD8 for the Detection of Cognitive Impairment in Geriatric Emergency Department Patients. Annals of emergency medicine, 57 (6), 653-61 PMID: 20855129

Measuring the ankle-brachial index using a stethoscope

February 25, 2009

Can we measure the ankle-brachial index using only a stethoscope? A pilot study. Fam Pract. 2009 Feb;26(1):22-6. Epub 2008 Nov 20. PMID: 19022870

The ankle-brachial index (ABI) by ausculation is less sensitive than an ABI of less than 0.9 by doppler ultrasonography and is less sensitive than an earlier report of the ABI by palpation.



Reference standard:


Last year, a study reported that the ankle-brachial index by palpation has a sensitivity and specificity of 88% and 82%, respectively as compared to handheld Doppler ultrasonography (PMID 18567610).

This has been added to