Remission of Severe Restless Legs Syndrome and Periodic Limb Movements in Sleep after Bilateral Excision of Multiple Foot Neuromas: A Case Report

Ludwig A Lettau; Charles J Gudas; Thomas D Kaelin

Disclosures

J Med Case Reports. 2010;4(306) 

In This Article

Discussion

Our patient's neuropathic foot dysesthesias first fully remitted after her initial neuroma surgery and again 5 years later after the second neuroma surgery. The first mild recurrence of dysesthesias resolved with stoppage of stavudine, a nucleoside HIV drug associated with neuropathic foot symptoms. Her HIV was fully suppressed with normal immune function throughout 10 years of treatment and was not considered to have any role in her ongoing symptoms otherwise. The remissions related to the two neuroma surgeries as well as the repeated improvements with neuroma injections indicate that her neuropathic foot dysesthesias were due to neuromas rather than small fiber neuropathy, which has been associated with diabetes and HIV infection.

Our patient clearly had RLS. Her symptoms fulfilled all the cardinal criteria for the diagnosis and her score of 36 on the 40-point International RLS rating scale was in the very severe range. The baseline polysomnogram showed a severe degree of PLMS and arousals. Over the next 4 months, despite a new regimen of drugs and additional neuroma injections, her foot dysesthesias, leg restlessness, non-restorative sleep, and fatigue all remained severe as shown by her pre-operative questionnaire and rating scale responses.

Surgery was recommended because of the severity and refractory nature of her symptoms. Excision of multiple neuromas was planned because (a) office ultrasound[10] documented large neuromas in the second and fourth metatarsal head interspaces in addition to stump neuromas of the third interspaces, (b) physical findings were present (Mulder's clicks in the third and fourth interspaces and tenderness in all three interspaces bilaterally), and (c) our (unpublished) neuroma injection experience has been that second and fourth interspace neuromas may contribute to neuropathic symptoms and sleep dysfunction, respectively.

Post-operatively her clinical improvement with respect to RLS symptoms, subjective sleep quality and neuropathic foot dysesthesias was immediate, and near total. That all symptoms originated peripherally from neuromas is supported by the histopathological documentation of the excised tissues and the fact she remained clinically well completely off neuropsychiatric medication for the initial six weeks after surgery. The follow-up polysomnography is notable for improved sleep efficiency and a substantial increase in REM sleep. It also documented both a marked reduction in arousals associated with PLMS and an apparent elimination of spontaneous arousals. The rapid reduction of her fatigue scores suggests that most of her fatigue was due to poor sleep quality.

We have previously proposed that the leg symptoms of RLS, and possibly also PLMS and arousals, may be due to afferent nerve impulses generated from the entrapment and compression-related digital nerve irritability and damage associated with foot neuromas,[9] and this hypothesis is supported by the clinical and polysomnographic results from our patient. In our cumulative experience with over 100 patients with RLS, we have determined that they uniformly have bilateral foot signs or ultrasound evidence of neuromas irrespective of whether they have foot sensory symptoms or not and regardless of whether their RLS is primary or secondary, or is of early or late onset. Third interspace neuromas would likely be the major source of RLS because bilateral injections of this interspace alone can induce remission of RLS symptoms.[9] The possible contribution to neuropathic foot symptoms and sleep dysfunction of the second and fourth interspace neuromas remains to be better delineated. That some PLMS still occurred post-operatively may reflect afferent impulses arising from her freshly cut digital nerve stumps. The eventual recurrence of mild leg restlessness and the relapse of neuropathic foot symptoms in our patient starting at seven weeks post-neuroma removal may indicate renewed nerve stump entrapment(s) as a result of digital nerve regrowth and scarring. This occurrence is the unpredictable downside of neuroma excision and it underscores the reality that current techniques for neuroma resection are not necessarily curative. However, although PLMS and arousals had likely also relapsed to some degree by two years out from the second neuroma surgery, her scores for sleep quality and fatigue remained much better than her pre-operative baseline and she has never regretted that she had had the multiple neuromas excised.

Comments

3090D553-9492-4563-8681-AD288FA52ACE
Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.

processing....