The Neurological Exam of a Comatose Patient: An Essential Practical Guide

A thorough examination of a comatose patient is essential given the spectrum of clinical diagnoses. The most immediate threat to patients is airway, breathing and circulation. All attending physician should employ a structured and focused approach in dealing with a comatose patient. It is important to recognise the urgent steps needed at the time to prevent further deterioration, followed by the final diagnosis of patient’s neurologic status. Here we provide the essential practical guide to the neurological exam of a comatose patient that would assist to determine the aetiology, location and nature of the neurological lesion.

The plantar reflex: A study of observer agreement, sensitivity, and observer bias

The utility of the plantar reflex in modern neurology is controversial. We studied the Babinski, Chaddock, and Oppenheim reflexes in terms of intraobserver, interobserver, and intertest agreement; sensitivity; positive predictive value (PPV); and observer bias. Sixty-two patients and 1,984 reflexes were analyzed. Intraobserver and interobserver agreement were weak (median κ <0.4). Intertest agreement was weak (median κ < 0.4) for all paired reflexes, although highest for the Babinski/Chaddock (0.30) (p < 0.05). There was no evidence of observer bias. Sensitivity was 59.7% for the Babinski, 55.3% for the Chaddock, and 30.0% for the Oppenheim. PPV was 70.3% for the Babinski, 66.5% for the Chaddock, and 61.3% for the Oppenheim. Our results show consistently low observer agreement for the plantar reflex. The Babinski and the Chaddock demonstrated comparable sensitivity and PPV.

Consistency of the Babinski reflex and its variants

BACKGROUND AND PURPOSE

The Babinski Reflex, first described in 1896, is still an integral part of the neurological examination. Many have studied the consistency of this reflex, but none have compared the inter- and intra-observer consistency of the Babinski reflex and its variants.

METHODS

Thirty-four subjects were examined by six neurologists. The Babinski, Gordon, Chaddock, and Oppenheim reflexes were tested, and each neurologist concluded if the plantar response was flexor or extensor. Six subjects were re-tested 1 week later to determine intra-observer consistency.

RESULTS

The Babinski reflex had the highest interobserver consistency with a kappa value of 0.5491. The Chaddock, Oppenheim, and Gordon reflexes had kappa values of 0.4065, 0.3739, and 0.3515, respectively. For intra-observer consistency, Gordon was the most consistent with a kappa value of 0.6731. When reflexes were combined in pairs, the Babinski and Chaddock reflexes together were the most reliable.

CONCLUSIONS

The Babinski reflex was shown to be the most consistent between examiners. The Gordon reflex had the highest intra-observer consistency; however, the small sample size should limit conclusions drawn from this calculation. Clinicians often utilize more than one reflex to examine the plantar response; the combination of the Babinski and Chaddock reflexes was the most reliable.

The frequency and significance of 'striatal toe' in parkinsonism

A striatal toe has been defined as an apparent extensor plantar response, without fanning of the toes, in the absence of any other signs suggesting dysfunction of the cortico-spinal tract. Little is known about the frequency and significance of this sign in parkinsonian syndromes. We prospectively examined 62 patients (Parkinson's disease: other akinetic-rigid syndromes=38:24) for the presence or absence of striatal toe and extensor plantar responses, as defined by Babinski. Details of the history, physical findings and investigations previously undertaken were rated and examined for their relevance to the response obtained from the hallux. Of the 62 patients, 17 patients showed an upgoing plantar response, of whom 13 (Parkinson's disease: other akinetic-rigid syndromes=7:6) had striatal toes, either unilateral (10) or bilateral (3). The remaining four patients showed a classical Babinski sign (Parkinson's disease: other akinetic-rigid syndromes=2:2). There was no lateralising relationship between lesions of the basal ganglia found on imaging and the side of the striatal toe, or the side of dyskinesias found at the time of examination. However, there appeared to be a greater frequency of dyskinesias and evidence of lesions involving the basal ganglia on imaging in patients with striatal toes compared with those who showed a plantar response other than upgoing. The possible relevance of these findings is discussed.

The Babinski sign: the first hundred years

The year 1996 marks the centenary of Babinski's description of the toe responses (normal and pathological) after stimulation of the sole of the foot. The upgoing toe response is normal in the 1st year of life and forms part of the flexion synergy of the leg, which had been known before 1896. Babinski also recognized the relation between the toe phenomenon (phénomène des orteils) in older children and adults and dysfunction of the pyramidal system. Neurologists became so fascinated by toe responses alone that many competing signs were proposed; most of these consisted of stimuli at other parts of the leg and were actually part of the same-but temporarily forgotten-flexion synergy. From 1910 to 1915 Marie and Foix and also Walshe re-emphasized this relationship and pointed out the analogy with the flexion reflex of the dog that had been extensively studied by Sherrington; the toe "extensors" shorten the leg and therefore they are flexors in a physiological sense. The normal (downward) toe response of the toes does not belong to a more complex movement, although Babinski originally believed this; it is a monosegmental skin reflex, akin to abdominal reflexes. Babinski correctly predicted that dysfunction of the pyramidal tract is not synonymous with a lesion, and that this dysfunction of the pyramidal system is necessary but not sufficient to produce a phénomène des orteils.

On the names of Babiński

The 100th anniversary of the discovery of the extensor plantar response will be celebrated in 1996. It was Joseph François Félix Babiński who became known worldwide for the sign that bears his name. In order to help Joseph in establishing his career, brother Henri gave up his aspirations and abandoned engineering. Clovis Vincent, "father' of French neurosurgery and pupil of Joseph, stated: "Joseph Babinski lived for science, and Henri lived for his brother; without Henri Babinski, Joseph would not have accomplished that much". However, Henri's name became famous in all Paris for a cookbook Gastronomie Pratique written under the pseudonym of "Ali-Bab.' Throughout Joseph's career his surname remained distorted despite his own efforts to spell and pronounce it correctly. Several people can claim the name Babiński, but in neurology and neurosurgery there is only one, Joseph.

The neurological assault on the great toe (1893-1911)

The late 19th/early 20th century heralded a period in neurology when there was claim and counter claim about the founders of new reflex movements of the great toe. The cutaneous plantar reflex is undoubtedly one of the most important signs in clinical neurology, and there have been several methods described of eliciting this sign, each with its own eponymous name. This article reviews the background to these claims and the contribution of the various authors, to the discovery, clinical relevance and ease of eliciting reflex movements of the great toe.