Characterization of Pain in Familial Amyloid Polyneuropathy.

Unlabelled: Familial amyloid polyneuropathy (FAP) caused by transthyretin (TTR) mutation is a small-fiber predominant polyneuropathy, exposing patients with TTR-FAP to development of neuropathic pain. However, the painful nature of TTR-FAP has never been specifically addressed. In this study, we compared 2 groups of 16 patients with either painless or painful TTR-FAP with regard to various clinical and neurophysiologic variables, including laser evoked potential (LEP) recording and quantitative sensory testing.

Spinal stimulation for movement disorders.

Epidural spinal cord stimulation (SCS) is currently proposed to treat intractable neuropathic pain. Since the 1970s, isolated cases and small cohorts of patients suffering from dystonia, tremor, painful leg and moving toes (PLMT), or Parkinson’s disease were also treated with SCS in the context of exploratory clinical studies. Despite the safety profile of SCS observed in these various types of movement disorders, the degree of improvement of abnormal movements following SCS has been heterogeneous among patients and across centers in open-label trials, stressing the need for larger, randomized, double-blind studies.

Sensory correlates of pain in peripheral neuropathies.

Objective: To characterize sensory threshold alterations in peripheral neuropathies and the relationship between these alterations and the presence of pain.

Methods: Seventy-four patients with length-dependent sensory axonal neuropathy were enrolled, including 38 patients with painful neuropathy (complaining of chronic, spontaneous neuropathic pain in the feet) and 36 patients with painless neuropathy. They were compared to 28 age-matched normal controls.

Predictive value of rTMS in the identification of responders to epidural motor cortex stimulation therapy for pain.

Unlabelled: This study was designed to assess the value of repetitive transcranial magnetic stimulation (rTMS) to predict the efficacy of epidural motor cortex stimulation (EMCS) to treat neuropathic pain. We have included 59 patients treated by EMCS for more than 1 year and in whom active and sham 10Hz-rTMS sessions were performed as preoperative tests, targeted over the cortical representation of the painful area. Analgesic effects were rated on a visual analogue scale.

Descending volleys generated by efficacious epidural motor cortex stimulation in patients with chronic neuropathic pain.

Epidural motor cortex stimulation (EMCS) is a therapeutic option for chronic, drug-resistant neuropathic pain, but its mechanisms of action remain poorly understood. In two patients with refractory hand pain successfully treated by EMCS, the presence of implanted epidural cervical electrodes for spinal cord stimulation permitted to study the descending volleys generated by EMCS in order to better appraise the neural circuits involved in EMCS effects. Direct and indirect volleys (D- and I-waves) were produced depending on electrode polarity and montage and stimulus intensity.

Cerebrovascular diseases in HIV-infected patients.

Cerebrovascular disease (CVD) has early been recognized in HIV-infected patients, including infectious arteritis, inflammatory vasculitis, aneurismal and small-vessel arteriopathy, to which adds now the premature atherosclerotic cerebral arteriopathy associated with the highly active antiretroviral therapy (HAART)-induced metabolic disorders. As a result of the increased life-expectancy associated with HAART, HIV patients grow older and are exposed to the combined vascular risk of antiviral-induced metabolic changes and advancing age. Several studies have documented subclinical cervical artery atherosclerosis, as assessed by intima-media thickness, ultrasound detection of carotid artery plaques and intracerebral small-vessel disease, all being associated with the induced metabolic changes.

The role of intra-operative motor evoked potentials in the optimization of chronic cortical stimulation for the treatment of neuropathic pain.

Objective: To explore the significance of intra-operative motor evoked potentials (MEPs) obtained by monopolar and bipolar stimulation in determining the location of the electrode(s) giving most pain relief in chronic motor cortex stimulation (MCS).

Methods: Eight patients with chronic refractory neuropathic pain were implanted epidurally with two parallel leads of four electrodes each and placed normal to the central sulcus (CS). We measured the peak-peak amplitude (V(p-p)) of the MEPs recorded intra-operatively at the contralateral hand with the same stimulus delivered by each single electrode used as an anode or a cathode.