Clinical criteria and diagnostic assessment of fibromyalgia: position statement of the Italian Society of Neurology-Neuropathic Pain Study Group.

BACKGROUND: The role of central and/or peripheral nervous system dysfunction is basically fundamental in fibromyalgia. AIM: The aim of this position statement on behalf of the Neuropathic Pain Study Group of the Italian Society of Neurology is to give practical guidelines for the clinical and instrumental assessment of fibromyalgia (FM) in the neurological clinical practice, taking into consideration recent studies. METHODS: Criteria for study selection and consideration were original studies, case-controls design, use of standardized methodologies for clinical practice, and FM diagnosis with ACR criteria (2010, 2011, 2016). RESULTS: ACR criteria were revised. For diagnostic procedure of small-fiber pathology, 47 studies were totally considered. Recent diagnostic criteria should be applied (ACR, 2016). A rheumatologic visit seems mandatory. The involvement of small fibers should request at least 2 among HRV + SSR and/or laser-evoked responses and/or skin biopsy and/or corneal confocal microscopy, eventually followed by monitoring of metabolic and/or immunological/ and or/paraneoplastic basis, to be repeated at 1-year follow-up. CONCLUSIONS: The correct diagnostic approach to FM could promote the exclusion of the known causes of small-fiber impairment. The research toward common genetic factors would be useful to promote a more specific therapeutic approach.

Ultrasound diagnosis of placental and umbilical cord anomalies in singleton pregnancies resulting from in-vitro fertilization.

INTRODUCTION: placental anomalies can affect fetal and maternal outcome due to severe maternal hemorrhage potentially resulting in hysterectomy and cord accident including abruption that can determine fetal damage or death. The aims of our study are to determine if the rate of placental and umbilical cord anomalies are more common in IVF singleton pregnancies compared to spontaneous pregnancies; to evaluate the role of ultrasound in screening for these anomalies and to investigate if oocyte donor fertilization is an additional risk factor for the development of these anomalies. METHODS: this was a prospective cohort study involving two tertiary centers. Patients with a singleton pregnancy conceived with IVF and patients presenting with a spontaneous conception were recruited between 1st May 2019 to 31st March 2021. A total of 634 pregnancies were enrolled in the study. All patients underwent similar antenatal care, which included ultrasound examinations at 11-14, 19-22 and 33-35 weeks. Ultrasound findings of placental and/or umbilical cord abnormalities were recorded using the same protocol for both groups and confirmed after birth. RESULTS: IVF pregnancies had a significantly higher risk of low-lying placenta, placenta previa, bilobed placenta and velamentous cord insertion (VCI) compared with spontaneous pregnancies. In the heterologous subgroup there was a significant increased incidence of placenta accreta spectrum (PAS) disorders than in spontaneous pregnancies. All these anomalies were identified prenatally on ultrasound imaging and confirmed at birth. DISCUSSION: IVF pregnancies in general and those resulting from donor oocyte in particular are at higher risk of placental and umbilical cord abnormalities compared to spontaneous pregnancies. These anomalies can be diagnosed accurately at the mid-trimester detailed fetal anomaly scan and our findings support the need for a targeted ultrasound screening of these anomalies in IVF pregnancies.

Modulation of the N13 component of the somatosensory evoked potentials in an experimental model of central sensitization in humans.

The N13 component of somatosensory evoked potential (N13 SEP) represents the segmental response of dorsal horn neurons. In this neurophysiological study, we aimed to verify whether N13 SEP might reflect excitability changes of dorsal horn neurons during central sensitization. In 22 healthy participants, we investigated how central sensitization induced by application of topical capsaicin to the ulnar nerve territory of the hand dorsum modulated N13 SEP elicited by ulnar nerve stimulation. Using a double-blind placebo-controlled crossover design, we also tested whether pregabalin, an analgesic drug with proven efficacy on the dorsal horn, influenced capsaicin-induced N13 SEP modulation. Topical application of capsaicin produced an area of secondary mechanical hyperalgesia, a sign of central sensitization, and increased the N13 SEP amplitude but not the peripheral N9 nor the cortical N20-P25 amplitude. This increase in N13 SEP amplitude paralleled the mechanical hyperalgesia and persisted for 120 min. Pregabalin prevented the N13 SEP modulation associated with capsaicin-induced central sensitization, whereas capsaicin application still increased N13 SEP amplitude in the placebo treatment session. Our neurophysiological study showed that capsaicin application specifically modulates N13 SEP and that this modulation is prevented by pregabalin, thus suggesting that N13 SEP may reflect changes in dorsal horn excitability and represent a useful biomarker of central sensitization in human studies.

A multi-institutional analysis of fractionated versus single-fraction stereotactic body radiotherapy (SBRT) in the treatment of primary lung tumors: a comparison between two antipodal fractionations.

OBJECTIVES: Stereotactic body radiotherapy (SBRT) is a consolidate treatment for inoperable early-stage lung tumors, usually delivered in single or multi-fraction regimens. We aimed to compare these two approaches in terms of local effectiveness, safety and survival. MATERIALS AND METHODS: Patients affected by medically inoperable early-stage lung tumor were treated at two Institutions with two different schedules: 70 Gy in ten fractions (TF) (BED10: 119 Gy) or 30 Gy in single fraction (SF) (BED10: 120 Gy). RESULTS: 73 patients were treated with SBRT delivered with two biological equivalent schedules: SF (44) and TF (29). The median follow-up was 34 months (range 3-81 months). Three-year Overall survival (OS) was 57.9%, 3-year cancer-specific survival (CSS) was 77.2%, with no difference between treatment groups. Three-year progression-free survival (LPFS) was 88.9% and did not differs between SF and TF. Overall, four cases (5.4%) of acute grade ≥ 3 pneumonitis occurred. No differences in acute and late toxicity between the two groups were detected. CONCLUSION: SF and TF seems to be equally safe and effective in the treatment of primary inoperable lung tumors especially for smaller lesion. The SF may be preferentially offered to reduce patient access to hospital with no negative impact on tumor control and survival.

Stereotactic ablative radiotherapy in castration-resistant prostate cancer patients with oligoprogression during androgen receptor-targeted therapy.

OBJECTIVES: To report outcomes of stereotactic body radiotherapy (SBRT) in metastatic castration-resistant prostate cancer (mCRPC) patients with oligoprogression (≤ 5 metastases) during first-line treatment with androgen receptor-targeted therapy (ARTT). PATIENTS AND METHODS: Retrospective multi-institutional analysis of mCRPC patients treated with SBRT to oligoprogressive lesions during ARTT. End-points were time to next-line systemic treatment (NEST), radiological progression-free survival (r-PFS) and overall survival (OS). Toxicity was registered according to Common Terminology Criteria for Adverse Events (CTCAE) v4.0. Survival analysis was performed using the Kaplan-Meier method, univariate and multivariate analysis (MVA) were performed. RESULTS: Data from 34 patients were analyzed. Median NEST-free survival, r-PFS, and OS were 16.97, 13.47, and 38.3 months, respectively. At MVA, factors associated with worse NEST-free survival and r-PFS were polymetastatic burden at diagnosis of metastatic hormone-sensitive disease (hazard ratio [HR] 3.66, p = 0.009; HR 3.03, p = 0.034), PSA ≤ 7 ng/ml at mCRPC diagnosis (HR 0.23, p = 0.017; HR 0.19, p = 0.006) and PSADT ≤ 3 months at mCRPC diagnosis (HR 3.39, p = 0.026; HR 2.79, p = 0.037). Polymetastatic state at mHSPC diagnosis was associated with a decreased OS (HR 4.68, p = 0.029). No patient developed acute or late grade ≥ 2 toxicity. CONCLUSION: Our results suggest that SBRT in oligoprogressive mCPRC is safe, effective and seems to prolong the efficacy of the ongoing systemic treatment positively affecting disease progression. Prospective trials are needed.

Markers of Cardiotoxicity in Early Breast Cancer Patients Treated With a Hypofractionated Schedule: A Prospective Study.

PURPOSE: To evaluate, in a series of early breast cancer (BC) patients treated with hypofractionated adjuvant radiotherapy (RT), whether N-terminal-pro hormone B-type natriuretic peptide (NT-proBNP) and high-sensitivity cardiac troponin I assay measurements can predict acute clinical or preclinical cardiotoxicity. PATIENTS AND METHODS: The study comprised 44 consecutive patients, who underwent conservative surgery with or without (neo)adjuvant chemotherapy and hypofractionated adjuvant RT. The RT schedule consisted in a total dose of 42.4 Gy in 16 fractions administered 5 days per week. Twenty-one patients received a subsequent boost to the tumor bed consisting of a total dose of 10 Gy in 4 fractions delivered via a direct electron field. All patients underwent 12-lead electrocardiogram, echocardiogram, and cardiac clinical examinations before RT to assess cardiovascular risk factors; these examinations were repeated yearly for 5 consecutive years. High-sensitivity cardiac troponin I and NT-proBNP were analyzed from serum samples at baseline, after delivery of the fourth and 16th RT fractions, and 12 months after treatment completion. RESULTS: No increase in cardiac troponin I and B-type natriuretic peptide levels related to left breast irradiation was observed. No statistical difference in NT-proBNP and high-sensitivity troponin I levels between left- and right-sided BC was found. An increase was observed of B-type natriuretic peptide levels at baseline, during treatment, and until 12 months after RT related to hypertension, with the P value near to the .05 threshold for age and chemotherapy. CONCLUSION: Conformational hypofractionated RT in left-sided BC may not cause acute myocardial damage. Early cardiac screening may be used to identify patients with cardiologic risk factors, patients who are older than 60 years, and patients who received chemotherapy that could result in clinically relevant cardiac pathologies.

Diagnosis of pediatric anti-NMDAR encephalitis at the onset: A clinical challenge.

BACKGROUNDS: To investigate the clinical and instrumental features at the onset addressing to the diagnosis of anti-NMDAR encephalitis. METHODS: Twenty children (age: 15 months-17 years; 7 males, 13 females) with initial suspected diagnosis of autoimmune encephalitis, observed between January 2008 and March 2018, were included. The final diagnosis was anti-NMDAR encephalitis in 7 children, other/probable autoimmune encephalitis in 7 children, and primary psychosis in the remaining 6 children. RESULTS: At the clinical onset, anxiety disorder was the main symptom that helped in distinguishing the group of psychotic children from children with non-infectious encephalitis (P = 0.05 OR = 0.001), while epileptic seizures strongly predicted anti-NMDAR encephalitis (P = 0.04 OR = 28.6). At the onset, anti-NMDAR encephalitis could be distinguished from other/probable autoimmune encephalitis for the presence of sleep/wake rhythm alteration (P = 0.05 OR = 15). Among the symptoms occurring during the hospitalization, movement disorders (P = 0.031 OR = 12) were predictive of non-infectious encephalitis rather than primary psychosis. More specifically, the occurrence of language impairment (P = 0.03 OR = 33), epileptic seizures (P = 0.04 OR = 28.6) and catatonia (P = 0.03, OR = 33), were predictive of anti-NMDAR encephalitis. Also at this stage, anxiety disorder (P = 0.03 OR = 0.033) was predictive of primary psychosis. CONCLUSION: Our findings suggest that at the clinical onset epileptic seizures and sleep/wake rhythm alteration represent the main features addressing to the diagnosis of anti-NMDAR encephalitis rather than primary psychosis and other/probable autoimmune encephalitis, while anxiety disorder could be a solid predictor of primary psychosis.

Local and metastatic curative radiotherapy in patients with de novo oligometastatic prostate cancer.

The aim of this observational study is to investigate whether local consolidative treatment delivered to the primary site and metastatic tumour burden may add survival benefit to de novo oligometastatic prostate cancer (Oligo-PCa) patients. We retrospectively reviewed all Oligo-PCa patients treated with radiotherapy to the primary tumor sites and metastatic tumor burden at our institution between March 2010 and June 2019. All patients having ≤ 5 metastases involving nodes and/or bones, loco-regional and/or extra-pelvic sites, were included. Most of the patients had started androgen deprivation therapy with or without docetaxel as standard of care before radiotherapy. The Kaplan Meier analysis was performed to estimate survival outcomes. The univariate analysis tested possible prognostic factors increasing the rate of biochemical relapse. We analysed 37 Oligo-PCa patients. Twenty-eight (75.7%) had loco-regional metastases, in 9 patients (24.3%) the metastatic tumour burden was extra-pelvic. Nineteen (51.4%) had bone metastases, 21 (56.8%) nodal involvement and 7 (18.9%) both. Twenty (54.1%) had a single metastasis. The median follow-up was 55.5 months. The median overall survival (OS) was 68.8 months, the 2- and 5-year OS rates were 96.9% and 65.4%. The median biochemical relapse free survival (b-RFS) was 58 months and the 2- and 5-year b-RFS rates were 73.3% and 39.3%. The 2- and 5-year local relapse free survival rates were 93.9% and 83.7%. On the univariate analysis post-treatment PSA level ≤ 1 ng/ml was significantly related with the b-RFS (p = 0.004). Curative approach in Oligo-PCa patients involving both the primary tumor and metastatic sites may be feasible and well tolerate. Many patients presented longer survival and PSA at first follow-up was the most important prognostic factor. Further trials are needed to confirm our results and to evaluate if patients with PSA at first follow-up > 1 ng/ml may benefit from further treatments.

Subgroup comparison according to clinical phenotype and serostatus in autoimmune encephalitis: a multicenter retrospective study.

BACKGROUND AND PURPOSE: Autoimmune encephalitides (AE) include a spectrum of neurological disorders whose diagnosis revolves around the detection of neuronal antibodies (Abs). Consensus-based diagnostic criteria (AE-DC) allow clinic-serological subgrouping of AE, with unclear prognostic implications. The impact of AE-DC on patients' management was studied, focusing on the subgroup of Ab-negative-AE. METHODS: This was a retrospective multicenter study on patients fulfilling AE-DC. All patients underwent Ab testing with commercial cell-based assays (CBAs) and, when available, in-house assays (immunohistochemistry, live/fixed CBAs, neuronal cultures) that contributed to defining final categories. Patients were classified as Ab-positive-AE [N-methyl-d-aspartate-receptor encephalitis (NMDAR-E), Ab-positive limbic encephalitis (LE), definite-AE] or Ab-negative-AE (Ab-negative-LE, probable-AE, possible-AE). RESULTS: Commercial CBAs detected neuronal Abs in 70/118 (59.3%) patients. Testing 37/48 Ab-negative cases, in-house assays identified Abs in 11 patients (29.7%). A hundred and eighteen patients fulfilled the AE-DC, 81 (68.6%) with Ab-positive-AE (Ab-positive-LE, 40; NMDAR-E, 32; definite-AE, nine) and 37 (31.4%) with Ab-negative-AE (Ab-negative-LE, 17; probable/possible-AE, 20). Clinical phenotypes were similar in Ab-positive-LE versus Ab-negative-LE. Twenty-four/118 (20.3%) patients had tumors, and 19/118 (16.1%) relapsed, regardless of being Ab-positive or Ab-negative. Ab-positive-AE patients were treated earlier than Ab-negative-AE patients (P = 0.045), responded more frequently to treatments (92.3% vs. 65.6%, P < 0.001) and received second-line therapies more often (33.3% vs. 10.8%, P = 0.01). Delays in first-line therapy initiation were associated with poor response (P = 0.022; odds ratio 1.02; confidence interval 1.00-1.04). CONCLUSIONS: In-house diagnostics improved Ab detection allowing better patient management but was available in a patient subgroup only, implying possible Ab-positive-AE underestimation. Notwithstanding this limitation, our findings suggest that Ab-negative-AE and Ab-positive-AE patients share similar oncological profiles, warranting appropriate tumor screening. Ab-negative-AE patients risk worse responses due to delayed and less aggressive treatments.

A Delphi consensus statement of the Neuropathic Pain Special Interest Group of the Italian Neurological Society on pharmacoresistant neuropathic pain.

To improve patient care and help clinical research, the Neuropathic Pain Special Interest Group of the Italian Neurological Society appointed a task force to elaborate a consensus statement on pharmacoresistant neuropathic pain. The task force included 19 experts in neuropathic pain. These experts participated in a Delphi survey consisting of three consecutive rounds of questions and a face-to-face meeting, designed to achieve a consensus definition of pharmacoresistant neuropathic pain. In the three rounds of questions, the participants identified and described the main distinguishing features of pharmacoresistance. In the face-to-face meeting the participants discussed the clinical features determining pharmacoresistance. They finally agreed that neuropathic pain is pharmacoresistant when "the patient does not reach the 50% reduction of pain or an improvement of at least 2 points in the Patient Global Impression of Change, having used all drug classes indicated as first, second, or third line in the most recent and widely agreed international guidelines, for at least 1 month after titration to the highest tolerable dose." Our consensus statement might be useful for identifying eligible patients for invasive treatments, and selecting patients in pharmacological trials, thus improving patient care and helping clinical research.

Salvage radiotherapy with simultaneous integrated boost in non small-cell lung cancer patients with mediastinal relapse after surgery: a pilot study.

BACKGROUND: The aim of our study was to evaluate feasibility, toxicity profile and local control of salvage intensity modulated radiotherapy (IMRT) delivered with simultaneous integrated boost (SIB) associated or not to concomitant weekly cisplatin in patients affected by NSCLC with mediastinal nodal recurrence after surgery. Patterns of recurrence, outcomes and prognostic factors were assessed. METHODS: Fourteen consecutive patients received 25 fractions of 50Gy/2Gy to the elective nodal stations and boost up to 62.5Gy/2.5Gy to the macroscopic lymph node metastases. Concomitant weekly cisplatin (40 mg/m2) was administered to 8 (57.1%) patients. RESULTS: Five (35.7%) patients experienced grade 2 pneumonitis and 5 (35.7%) patients had grade 2 esophagitis. One case of grade 3 pneumonitis occurred and was successfully treated with antibiotics and steroids with no sequelae. No patient recurred locally in the boost volume (local control 100%). Loco-regional control was 79% with 3 patients that developed nodal recurrence principally marginal to the elective volume. Seven patients developed distant metastases. Median PFS was 7 months. The nodal involvement of station 7 was associated to a significantly lower median metastasis-free survival (4 months vs. not reached, p = 0.036). CONCLUSIONS: Salvage radiotherapy with IMRT-SIB is a feasible and a well-tolerated treatment option for mediastinal recurrent NSCLC after surgery. The role of more intensified radiation regimens and association to systemic therapy remain to be evaluated in larger cohorts.

30 Gy single dose stereotactic body radiation therapy (SBRT): Report on outcome in a large series of patients with lung oligometastatic disease.

OBJECTIVES: To evaluate the local control (LC) and long term adverse effects in a series of patients with lung metastases who received 30 Gy in single dose with stereotactic technique. MATERIALS AND METHODS: Between December 2008 and April 2016, a total of 166 lung metastases in 129 patients affected by oligometastatic disease were treated at our Institution with stereotactic body radiotherapy (SBRT). Mainly, the primary tumors were non small-cell lung cancer and colorectal cancer (45.2% and 28.8%, respectively). Prognostic factors were also assessed. RESULTS: The median follow-up was 38 months. Local progression occurred in 24 (14.4%) lesions in 21 patients. Intra-thoracic progression (new lung lesions or thoracic lymph node metastases) occurred in 59 (45.7%) patients. Forty-five (34.8%) patients had distant progression after a median time of 14 months. The 3- and 5-years local relapse-free survival (LPFS) were 80.1% and 79.2% (median not reached), respectively. One-hundred forty-eight patients were evaluated for late toxicity (follow-up >6 months): 51 (34.4%) patients had grade ≤2 fibrosis, 11 (7.4%) patients experienced grade 3 fibrosis. Two (1.3%) cases of rib fracture occurred. One case of toxic death (grade 5) has been reported. Median OS was 39 months. At the univariate analysis, lesion diameter ≤18 mm correlated significantly with a longer LPFS (p = 0.001). At the multivariate analysis, lesion diameter <18 mm was predictive for longer LPFS (p = 0.006). Also, oligometastases from primary colorectal cancer was a significant predictive factor for worse LPFS (p = 0.041) and progression-free survival (p = 0.04). CONCLUSIONS: To our knowledge, the current study represents the largest series on the use of SBRT 30 Gy single dose for lung metastases. Our results confirm the effectiveness and safety of this schedule administered in selected oligometastatic patients. Further prospective series could better validate these results.

Skin denervation does not alter cortical potentials to surface concentric electrode stimulation: A comparison with laser evoked potentials and contact heat evoked potentials.

BACKGROUND: In the neurophysiological assessment of patients with neuropathic pain, laser evoked potentials (LEPs), contact heat evoked potentials (CHEPs) and the evoked potentials by the intraepidermal electrical stimulation via concentric needle electrode are widely agreed as nociceptive specific responses; conversely, the nociceptive specificity of evoked potentials by surface concentric electrode (SE-PREPs) is still debated. METHODS: In this neurophysiological study we aimed at verifying the nociceptive specificity of SE-PREPs. We recorded LEPs, CHEPs and SE-PREPs in eleven healthy participants, before and after epidermal denervation produced by prolonged capsaicin application. We also used skin biopsy to verify the capsaicin-induced nociceptive nerve fibre loss in the epidermis. RESULTS: We found that whereas LEPs and CHEPs were suppressed after capsaicin-induced epidermal denervation, the surface concentric electrode stimulation of the same denervated skin area yielded unchanged SE-PREPs. CONCLUSION: The suppression of LEPs and CHEPs after nociceptive nerve fibre loss in the epidermis indicates that these techniques are selectively mediated by nociceptive system. Conversely, the lack of SE-PREP changes suggests that SE-PREPs do not provide selective information on nociceptive system function. SIGNIFICANCE: Capsaicin-induced epidermal denervation abolishes laser evoked potentials (LEPs) and contact heat evoked potentials (CHEPs), but leaves unaffected pain-related evoked potentials by surface concentric electrode (SE-PREPs). These findings suggest that unlike LEPs and CHEPs, SE-PREPs are not selectively mediated by nociceptive system.

Trigeminal laser-evoked potentials: a neurophysiological tool to detect post-surgical outcome in trigeminovascular contact neuralgia.

BACKGROUND: The aim of this study was to explore the nociceptive system of patients affected by trigeminal neuralgia (TN) secondary to documented vascular contact who underwent microvascular decompression. For that purpose, we used the classical trigeminal reflexes and the trigeminal laser-evoked potentials (tLEPs) before and after surgery, in order to verify any possible change after decompression and determine if there was any correlation between the neurophysiological parameters and the clinical outcome. METHODS: Eleven patients affected by TN caused by trigeminovascular contact and 10 age-matched controls underwent conventional trigeminal reflexes (bilateral Blink Reflex/BR and Masseter Inhibitory Reflex stimulating infraorbital and mental nerves/MIR V2 and V3) and tLEPs. Patients repeated neurophysiological tests one week after surgery. RESULTS: Short-latency BR and MIR were normal in all patients before surgery and there was no statistical difference before and after surgery. Conversely, in patients before surgery, tLEPs' amplitudes were significantly lower in the affected than in the healthy side (p = 0.017 for V2 and 0.037 for V3 branches). After surgery, on the affected side, tLEP amplitude increased and the pre/post-operative difference was significant (p = 0.017 for V2 and 0.028 for V3 divisions). Nine patients referred satisfactory pain relief and the favourable clinical outcome correlated with the neurophysiological recovery. CONCLUSIONS: This study demonstrates that TN caused by trigeminovascular compression may be related to Aδ fibres impairment, and tLEPs are more sensitive than conventional trigeminal reflexes to reveal small fibre dysfunction and to monitor the post-surgical outcome in these patients.

Abdominal acupuncture reduces laser-evoked potentials in healthy subjects.

OBJECTIVE: Acupuncture is known to reduce clinical pain, although the exact mechanism is unknown. The aim of the current study was to investigate the effect of acupuncture on laser-evoked potential amplitudes and laser pain perception. METHODS: In order to evaluate whether abdominal acupuncture is able to modify pain perception, 10 healthy subjects underwent a protocol in which laser-evoked potentials (LEPs) and laser pain perception were collected before the test (baseline), during abdominal acupuncture, and 15 min after needle removal. The same subjects also underwent a similar protocol in which, however, sham acupuncture without any needle penetration was used. RESULTS: During real acupuncture, both N1 and N2/P2 amplitudes were reduced, as compared to baseline (p<0.01). The reduction lasted up to 15 min after needle removal. Furthermore, laser pain perception was reduced during real acupuncture, although the difference was marginally significant (p=0.06). CONCLUSIONS: Our results show that abdominal acupuncture reduces LEP amplitude in healthy subjects. SIGNIFICANCE: Our results provide a theoretical background for the use of abdominal acupuncture as a therapeutic approach in the treatment of pain conditions. Future studies will have to be conducted in clinical painful syndromes, in order to confirm the analgesic effect of acupuncture in patients suffering from pain.

Somatosensory system hyperexcitability in alternating hemiplegia of childhood.

BACKGROUND AND PURPOSE: Alternating hemiplegia of childhood (AHC) is a rare neurological disease characterized by recurrent paroxysmal attacks of hemiplegia. The aim of the study was to assess the recovery cycle of the somatosensory evoked potentials (SEPs) in a group of AHC patients. METHODS: Seven AHC patients and 10 control age-matched subjects (CS) were recruited. Right and left median nerve SEPs were recorded. The somatosensory system excitability was assessed by calculating the SEP changes after paired electrical stimuli. All patients were studied during the interictal phase, whilst four patients were studied also during the ictal phase. RESULTS: In AHC patients during the interictal phase, the amplitudes of the cervical N13 and of the cortical N20, P24 and N30 responses showed a faster recovery than in CS. In AHC patients during the ictal phase, the cortical N20 recovery cycle was prolonged compared with the interictal phase. CONCLUSIONS: A shortened SEP recovery cycle in AHC during the interictal phase suggests multilevel somatosensory system hyperexcitability in AHC. A partial recovery of this phenomenon during the ictal phase possibly reflects a functional reset of the somatosensory system. Overall, there is a disinhibition of the somatosensory system in AHC, a functional change of brain function associated with a possible involvement of the Na(+) /K(+) channels. This abnormality and its partial recovery during the attacks might be linked to the pathophysiological and genetic mechanisms of the disease.