Nerve conduction in Morton's Interdigital Neuroma

NewsBot · Oct 26, 2007

Members do not see these Ads. Sign Up.
Abnormal dip phenomenon: a characteristic electrophysiological marker in interdigital neuropathy of the foot.
Almeida DF, Kurokawa K, Hatanaka Y, Hemmi S, Claussen GC, Oh SJ.
Arq Neuropsiquiatr. 2007 Sep;65(3B):771-8.

OBJECTIVE: The nerve conduction findings in interdigital neuropathy of the foot (IDN; Morton's neuroma) have rarely been reported. We analyzed the nerve conduction data in 23 patients with suspected IDN studied between 1982 and 2002.

METHOD: Diagnosis of IDN was made on the basis of clinical features. All patients underwent routine nerve conduction studies and a near-nerve needle sensory nerve conduction study of the interdigital nerves by Oh's method in the symptomatic foot.

RESULTS: Of the 23 patients, the diagnosis of definite IDN was made in 13 cases and of possible NDN in the others cases. Nineteen were females. Twenty two patients had only one nerve affected. One patient had two nerves affected. The III-IV interdigital nerve was affected in 17 cases and the II-III interdigital nerve in 7 cases. The near-nerve needle nerve conduction showed abnormality in the affected interdigital nerves in all definite IDN cases and confirmed the diagnosis of IDN in 10 cases by the abnormal dip phenomenon (a selective decrease of 50% or more in the sensory CNAP amplitude of the affected nerve compared with that of the preceding interdigital nerve). In 11 possible IDN cases, IDN was identified by the abnormal dip phenomenon.

CONCLUSION: The near-nerve needle sensory nerve conduction of the interdigital nerves is a highly sensitive diagnostic test, and abnormal dip phenomenon is the most characteristic electrophysiological marker for the diagnosis of IDN
Click to expand...

Admin2 · Oct 26, 2007

Related threads:
Injection vs ultrasound for neuroma diagnosis
Morton's Neuroma Questions: dancer researching options
Mortons Neuroma

NewsBot · Sep 9, 2010

Sensory nerve conduction in branches of common interdigital nerves: a new technique for normal controls and patients with morton's neuroma.
Uludag B, Tataroglu C, Bademkiran F, Uludag IF, Ertekin C.
J Clin Neurophysiol. 2010 Jun;27(3):219-23.

In this article, a new electrodiagnostic approach is described for patients with Morton's neuroma. The new method is based on the anatomic fact that the two branches of the common plantar interdigital nerves innervate the lateral side of one toe and the medial side the next one. This study included 20 normal subjects (aged 28-58 years, 10 men and 10 women) and 4 patients with Morton's neuroma (aged 44-52 years, 4 women). The branches of adjacent common plantar interdigital nerves that innerve one toe were stimulated superficially and separately with half of one toe covered with a piece of medical tape. The recordings were obtained on the posterior tibial nerve at the medial malleolus with needle electrodes. Thus, the difference in latencies of obtained sensory nerve action potentials on the posterior tibial nerve with needle electrode was measured. From normal subjects' data, it was determined that a latency difference value of above 0.17 milliseconds (mean +/- 2.5 SD) in one toe was abnormal. All of the patients with Morton's neuroma showed abnormal interlatency difference values. This new method, which we have developed, is more sensitive, simple to use, does not require extra equipment, and does not cause excessive pain. We suggest that interlatency difference between branches of the common plantar interdigital nerves is a useful and sensitive method for the diagnosis of Morton's neuroma.
Click to expand...

NewsBot · Sep 24, 2017

Sensory Mapping in Patients Following Excision of a Morton’s Neuroma
Maryam Jan, MBBS, Jayasree Ramas Ramaskandhan, MD, Paulo Torres, FRCS(Ed)
Foot & Ankle Orthopaedics September 18, 2017

Introduction/Purpose:
Background: Morton’s neuromata are a common cause of forefoot pain. Surgical excision of the neuroma is expected to result in loss of sensation, however in the author’s experience post-operative sensation can be incongruent with the expected cutaneous innervation of the excised nerve. There is a lack of literature regarding this observed discrepancy. The purpose of this study was to carry out sensory mapping in post excision patients.

Methods:
Methods: Data was collated from the consecutive case series of a single surgeon from 2013-2015 resulting in a total of 19 respondents (23 excisions). All patients were a minimum of 7 months post-excision (average=23 months). Each toe was divided into 13 anatomical segments (total 65). Sensation was assessed using a 10 g monofilament and results were recorded on a sensory map.

Results:
19 excisions were done from the 3 rd intermetatarsal space (group A) and 4 from the 2nd intermetatarsal space (group B). The range of patients from group A affected by complete sensory loss within any individual segment varied from 5.3%-47.4%. In the lesser toes (2, 3, 4 and 5), at least 10% of patients described decreased or absent sensation in =7/13 segments in each of all the lesser toes.

Over 36.9% of patients reported decreased or absent sensation involving =7/13 segments in each the 3 rd and 4th toes. The percentage of patients who reported unaltered sensation ranged from 21.1%-100% across all 65 segments. Group B followed a similar pattern but had a much smaller cohort of patients.

Conclusion:
The results of the sensory mapping indicate an unexpected pattern of loss and preservation of sensation when considering the perceived knowledge of the cutaneous innervation of the forefoot. Further research is required to evaluate this intriguing pattern of innervation. A greater understanding would be useful in better informing our patients during the consent process.
Click to expand...

NewsBot The Admin that posts the news.

Admin2 Administrator Staff Member

NewsBot The Admin that posts the news.

NewsBot The Admin that posts the news.

Nerve Conduction Test For Foot

Nerve Conduction Tests

Nerves around hallux valgus

Tibial Nerve Block as Treatment of Chronic Foot Pain

Nerve Pain After Surgery

Sural Nerve anatomy

Lisfranc Injury with Nerve Damage

Share This Page