Intra-Arterial Thrombolysis to Improve Final Thrombolysis in Cerebral Infarction Score after Thrombectomy: A Case-Series Analysis.

Endovascular thrombectomy is the standard treatment in selected patients with acute ischemic stroke and large vessel occlusion, but continuous improvement in angiographic and clinical outcome is still needed. Intra-arterial thrombolysis has been tested as a possible rescue tool in unsuccessful thrombectomy, or as an adjuvant therapy after the endovascular procedure, to pursue complete recanalization. Here we present a case series analysis of intra-arterial alteplase administration (5 mg bolus, repeated up to 15 mg if Thrombolysis in Cerebral Infarction (TICI) scale ≥2c is not achieved) in 15 consecutive anterior circulation stroke patients after unsuccessful thrombectomy, defined as TICI score ≤2b after at least 3 passes or if unsuitable for further endovascular attempts, with the aim of improving recanalization. An improvement of final TICI score was achieved in 10 of 15 patients (66.7%). TICI score ≥2c was achieved after 5 mg intra-arterial tissue plasminogen activator (iaTPA) in 4 patients, and after 10 mg iaTPA in 5 cases. Six of 15 patients received 15 mg iaTPA: 1 of 6 showed angiographical improvement. A major effect of intra-arterial alteplase was observed for distally migrated emboli. None of the patients experienced any symptomatic hemorrhagic transformation or other major bleeding. Our report shows, in a very small cohort, a high rate of final TICI score improvement, encouraging the development of randomized controlled trials of rescue intra-arterial thrombolysis in patients with suboptimal angiographic results after mechanical thrombectomy.

A retrospective multicentric study on the effectiveness of intravenous brivaracetam in seizure clusters: Data from the Italian experience.

OBJECTIVE: Nearly half of people with epilepsy (PWE) are expected to develop seizure clusters (SC), with the subsequent risk of hospitalization. The aim of the present study was to evaluate the use, effectiveness and safety of intravenous (IV) brivaracetam (BRV) in the treatment of SC. METHODS: Retrospective multicentric study of patients with SC (≥ 2 seizures/24 h) who received IV BRV. Data collection occurred from January 2019 to April 2022 in 25 Italian neurology units. Primary efficacy outcome was seizure freedom up to 24 h from BRV administration. We also evaluated the risk of evolution into Status Epilepticus (SE) at 6, 12 and 24 h after treatment initiation. A Cox regression model was used to identify outcome predictors. RESULTS: 97 patients were included (mean age 62 years), 74 (76%) of whom had a history of epilepsy (with drug resistant seizures in 49% of cases). BRV was administered as first line treatment in 16% of the episodes, while it was used as first or second drug after benzodiazepines failure in 49% and 35% of episodes, respectively. On the one hand, 58% patients were seizure free at 24 h after BRV administration and no other rescue medications were used in 75 out of 97 cases (77%) On the other hand, SC evolved into SE in 17% of cases. A higher probability of seizure relapse and/or evolution into SE was observed in patients without a prior history of epilepsy (HR 2.0; 95% CI 1.03 - 4.1) and in case of BRV administration as second/third line drug (HR 3.2; 95% CI 1.1 - 9.7). No severe treatment emergent adverse events were observed. SIGNIFICANCE: In our cohort, IV BRV resulted to be well tolerated for the treatment of SC and it could be considered as a treatment option, particularly in case of in-hospital onset. However, the underlying etiology seems to be the main outcome predictor.

Small-fibre damage is associated with distinct sensory phenotypes in patients with fibromyalgia and small-fibre neuropathy.

BACKGROUND: In this clinical and psychophysical study, we aimed to verify whether patients with fibromyalgia with and without small-fibre pathology and patients with pure small-fibre neuropathy share common sensory phenotypes. METHODS: Using an algorithm based on quantitative sensory testing variables, we grouped 64 consecutive patients with fibromyalgia (20 with small-fibre pathology, 44 without) and 30 patients with pure small-fibre neuropathy into different sensory phenotypes: sensory loss, thermal hyperalgesia, mechanical hyperalgesia and healthy phenotypes. RESULTS: We found that the frequency of the different sensory phenotypes differed markedly between patients with fibromyalgia and patients with small-fibre neuropathy. In patients with fibromyalgia, with and without small-fibre pathology, healthy and hyperalgesia phenotypes (both thermal and mechanical) were similarly represented, whilst sensory loss and mechanical hyperalgesia phenotypes were the most frequent phenotypes in patients with small-fibre neuropathy. CONCLUSIONS: Our findings indicate that small-fibre damage is associated with distinct sensory phenotypes in patients with fibromyalgia and in patients with small-fibre neuropathy. The lack of phenotype differences between patients with fibromyalgia with and without small-fibre pathology and the relatively high frequency of the healthy phenotype in these patients highlight a complex relationship between small-fibre pathology and pain in patients with fibromyalgia.

Functional and morphometric assessment of small-fibre damage in late-onset hereditary transthyretin amyloidosis with polyneuropathy: the controversial relation between small-fibre-related symptoms and diagnostic test findings.

INTRODUCTION: We aimed at investigating whether functional and morphometric tests assessing small-fibre damage, ie quantitative sensory testing, Sudoscan and skin biopsy, reliably reflect neuropathic pain and autonomic symptoms in patients with late-onset hereditary transthyretin amyloidosis with polyneuropathy (ATTRv-PN). METHODS: In 30 patients with late-onset ATTRv-PN, we collected quantitative sensory testing, Sudoscan and skin biopsy with assessment of intraepidermal, piloerector muscle and sweat gland nerve fibre density. We then correlated these functional and morphometric parameters with neuropathic pain and autonomic symptoms as assessed with the Neuropathic Pain Symptom Inventory (NPSI) and Composite Autonomic Symptom Score-31 (COMPASS-31). RESULTS: 50% of patients showed small-fibre damage in the form of a pure small-fibre neuropathy, 47% in the context of a mixed fibre neuropathy with small and large fibre involvement. All patients complained of at least one autonomic symptom and 60% had neuropathic pain. Whereas quantitative sensory testing and Sudoscan parameters correlated with neuropathic pain and autonomic symptoms as assessed by NPSI and COMPASS-31, intraepidermal, piloerector muscle and sweat gland nerve fibre density quantification did not. CONCLUSIONS: Our findings indicate that functional test parameters reliably reflect neuropathic pain and autonomic symptoms related to small-fibre damage. These findings might help to identify clinically useful biomarkers to assess patient follow-up.

Skin biopsy and quantitative sensory assessment in an Italian cohort of ATTRv patients with polyneuropathy and asymptomatic carriers: possible evidence of early non-length dependent denervation.

AIM: Study of intraepidermal nerve fiber density (IENFD) by skin biopsy represents a promising tool in the evaluation of patients with ATTRv polyneuropathy (ATTRv-PN). Herein, we retrospectively analyze intraepidermal innervation and quantitative sensory test (QST) data from an Italian cohort of Italian ATTRv-PN patients and asymptomatic carriers aimed to provide insights into early nerve pathological and functional changes in this disease. METHODS: IENFD and QST data of 14 ATTRv-PN patients and 14 asymptomatic carriers were retrospectively analyzed together with clinical and paraclinical data such as disease stage and severity, neuropathic pain scales, and sural SNAP amplitude. RESULTS: Given an estimated time to the predicted age of onset of symptomatic disease of 20.27 + / - 7.9 years, small nerve fiber loss seems to be unexpectedly early in carriers. Moreover, carriers showed skin denervation at the proximal (thigh) site, suggesting a non-length-dependent neuropathic process. IENFD at ankle correlated with disease severity and other paraclinical variables such as sural nerve potential amplitude and QST parameters. Patients at earlier stages of the disease did not show significant differences in ankle IENFD compared with asymptomatic carriers, but significant differences in terms of QST parameters, small fiber neuropathy symptoms, and neuropathic pain. CONCLUSIONS: Skin biopsy can disclose an early non-length-dependent small fiber loss in ATTRv-PN and, together with QST, could provide a useful insight disease onset and progression.

Atypical Clinical and Neuroradiological Findings in a Child With Bifacial Weakness With Paresthesias.

BACKGROUND: Guillain-Barré syndrome (GBS) is the broad term used to describe a number of related acute autoimmune neuropathies, which together form a continuous spectrum of variable and overlapping syndromes. Bifacial weakness with paresthesias (BFP) is a rare variant of GBS, characterized by isolated facial diplegia in the absence of ophthalmoplegia, ataxia, or limb weakness, and it is usually associated with distal limb paresthesias. CASE DESCRIPTION: An 8-year-old boy was brought to our attention; because 5 days before coming to the hospital, he noticed he could no longer smile. Bilateral facial droop and inability to close both eyes were evident along with slight paresthesias at the hands and feet and gait disturbances. He progressively developed hypophonia, dysarthria, dysphagia associated with dysmetria, and limb ataxia. Nerve conduction studies showed a demyelinating polyneuropathy. Brain and spine magnetic resonance imaging (MRI) revealed contrast enhancement of both facial nerves and cauda equina nerve roots along with a hyperintense signal of the periaqueductal gray matter, superior cerebellar peduncles, and pontine tegmentum. Because BFP is not typically associated with other cranial neuropathies or ataxia, these clinical features along with peculiar MRI findings supported the diagnosis of "BFP plus." Finally, it can be speculated that this case configures a rare overlap between BFP and the other GBS variants, such as Bickerstaff encephalitis. CONCLUSIONS: This atypical case underlines the potential role of MRI in contributing to refining the nosological classification of GBS spectrum and optimizing individual treatment, especially in children where unusual manifestations are not infrequent and neurological examination is more challenging.

Differential involvement of myelinated and unmyelinated nerve fibers in painful diabetic polyneuropathy.

BACKGROUND: We aimed at evaluating the differential involvement of large myelinated Aß-, small myelinated Aδ-, and unmyelinated C-fibers in patients with diabetic polyneuropathy and how they contribute to neuropathic pain. METHODS: We collected clinical and diagnostic test variables in 133 consecutive patients with diabetic polyneuropathy. All patients underwent Aß-fiber mediated nerve conduction study, Aδ-fiber mediated laser-evoked potentials and skin biopsy mainly assessing unmyelinated C-fibers. RESULTS: Pure large-fiber and small-fiber polyneuropathy were relatively uncommon; conversely mixed-fiber polyneuropathy was the most common type of diabetic polyneuropathy (74%). The frequency of neuropathic pain was similar in the three different polyneuropathies. Ongoing burning pain and dynamic mechanical allodynia were similarly associated with specific small-fiber related variables. CONCLUSIONS: Diabetic polyneuropathy mainly manifests as a mixed-fiber polyneuropathy, simultaneously involving Aß-, Aδ-, and C-fibers. In most patients, neuropathic pain is distinctly associated with small-fiber damage. The evidence that the frequency of neuropathic pain does not differ across pure large-, pure small-, and mixed-fiber polyneuropathy, raises the possibility that in patients with pure large-fiber polyneuropathy nociceptive nerve terminal involvement might be undetected by standard diagnostic techniques.

Painful stimulation increases spontaneous blink rate in healthy subjects.

Spontaneous blink rate is considered a biomarker of central dopaminergic activity. Recent evidence suggests that the central dopaminergic system plays a role in nociception. In the present study, we aimed to investigate whether pain modulates spontaneous blink rate in healthy subjects. We enrolled 15 participants. Spontaneous blink rate was quantified with an optoelectronic system before and after: (1) a painful laser stimulation, and (2) an acoustic startling stimulation. In control experiments, we investigated whether laser stimulation effects depended on stimulation intensity and whether laser stimulation induced any changes in the blink reflex recovery cycle. Finally, we investigated any relationship between spontaneous blink rate modification and pain modulation effect during the cold pressor test. Laser, but not acoustic, stimulation increased spontaneous blink rate. This effect was independent of stimulation intensity and negatively correlated with pain perception. No changes in trigeminal-facial reflex circuit excitability were elicited by laser stimulation. The cold pressor test also induced an increased spontaneous blink rate. Our study provides evidence on the role of dopamine in nociception and suggests that dopaminergic activity may be involved in pain modulation. These findings lay the groundwork for further investigations in patients with pathological conditions characterized by dopaminergic deficit and pain.

Small-fibre pathology has no impact on somatosensory system function in patients with fibromyalgia.

We aimed to investigate whether small-fibre pathology, a common skin biopsy finding in patients with fibromyalgia, implies clinically important abnormalities of somatosensory system function and verify whether it is associated with voltage-gated sodium channel variants. In 57 consecutively enrolled patients with fibromyalgia, we used skin biopsy to distinguish patients with and without small-fibre pathology. In all patients, we assessed somatosensory system function using quantitative sensory testing (QST) and laser-evoked potentials and investigated voltage-gated sodium channel genotyping. We then compared these variables in patients with and without small-fibre pathology. We found that clinical measures, QST, and laser-evoked potential variables did not differ between patients with and without small-fibre pathology. In most patients with small-fibre pathology, QST and laser-evoked potential variables fell within normative ranges commonly used in clinical practice. Of the 57 patients, one patient without small-fibre pathology and 2 patients with small-fibre pathology had rare variants of voltage-gated sodium channels, namely SCN11A, SCN9A, and SCN1A variants. The SCN9A variant, found in a patient with small-fibre pathology, was an already profiled gain-of-function mutation, previously reported in small-fibre neuropathy. Our findings suggest that small-fibre pathology has a negligible impact on somatosensory system function in fibromyalgia. The genetic analysis suggests that patients with rare small-fibre neuropathy due to voltage-gated sodium channel variants may be misdiagnosed as patients with fibromyalgia.

Pain due to Ehlers-Danlos Syndrome Is Associated with Deficit of the Endogenous Pain Inhibitory Control.

OBJECTIVES: Although pain is a common complication of the hypermobile type of Ehlers-Danlos syndrome, its underlying mechanisms are still an issue of controversy. In this psychophysical study, we aimed at testing small-fiber function and the endogenous pain inhibitory control in patients with pain due to Ehlers-Danlos syndrome. METHODS: In 22 patients with pain due to Ehlers-Danlos syndrome and 22 healthy participants, matched for age and sex, we tested small-fiber function using quantitative sensory testing and the endogenous pain inhibitory control using the conditioned pain modulation (CPM) protocol. As quantitative sensory testing methods, we included thermal pain and mechanical pain thresholds and the wind-up ratio. The CPM protocol consisted of two heat painful stimuli, that is, a test stimulus and a conditioning stimulus. RESULTS: All patients complained of widespread pain. Quantitative sensory testing revealed no small-fiber deficit; in the area of maximum pain, we found an increased wind-up ratio. Whereas in the healthy participants the CPM protocol showed that the test stimulus rating was significantly reduced during conditioning, in patients with pain due to hEDS, the test stimulus rating increased during conditioning. CONCLUSIONS: Our psychophysical study showing that patients with pain due to hEDS have an increased wind-up ratio in the area of maximum pain and abnormal CPM protocol suggests that in this condition, pain is associated with central sensitization, possibly due to deficit of the endogenous pain inhibitory control. These data might be relevant to pharmacological treatment.

The new micropatterned interdigitated electrode for selective assessment of the nociceptive system.

BACKGROUND: In this neurophysiological study, we aimed at verifying the nociceptive selectivity of the new, micropatterned electrode (150IDE), recently designed to generate an electric field limited to the intraepidermal free nerve endings. METHODS: Using the new 150IDE, we recorded evoked potentials after stimulation of the face and hand dorsum in 22 healthy participants and in patients with exemplary conditions selectively affecting the nociceptive system. We also measured the peripheral conduction velocity at the upper arm and verified the nociceptive selectivity of 150IDE assessing the effect of a selective block of nociceptive nerve fibres of radial nerve with local anaesthetic infiltration. In healthy participants and in patients, we have also compared the 150IDE-evoked potentials with laser-evoked potentials. RESULTS: In healthy participants, the 150IDE-evoked pinprick sensation and reproducible scalp potentials, with latency similar to laser-evoked potentials. The mean peripheral conduction velocity, estimated at the upper arm, was 12 m/s. The selective nociceptive fibre block of the radial nerve abolished the scalp potentials elicited by the 150IDE stimulation. In patients, the 150IDE-evoked potentials reliably detected the selective damage of the nociceptive system. CONCLUSIONS: Our neurophysiological study shows that this new 150IDE provides selective information on nociceptive system. SIGNIFICANCE: 150IDE is a promising new tool for investigating nociceptive system in patients with neuropathic pain.

Cooling the skin for assessing small-fibre function.

In this clinical and neurophysiological study using a novel cold stimulator, we aim at investigating whether cold-evoked potentials (CEPs) may prove to be a reliable diagnostic tool to assess trigeminal small-fibre function. Using a novel device consisting of micro-Peltier elements, we recorded CEPs after stimulating the supraorbital and perioral regions and the hand dorsum in 15 healthy participants and in 2 patients with exemplary facial neuropathic pain conditions. We measured peripheral conduction velocity at the upper arm and studied the brain generators using source analysis. In healthy participants and patients, we also compared CEPs with laser-evoked potentials. In the healthy participants, cold stimulation evoked reproducible scalp potentials, similar to those elicited by laser pulses, although with a latency of about 30 ms longer. The mean peripheral conduction velocity, estimated at the upper arm, was 12.7 m/seconds. The main waves of the scalp potentials originated from the anterior cingulate gyrus and were preceded by activity in the bilateral opercular regions and bilateral dorsolateral frontal regions. Unlike laser stimulation, cold stimulation evoked scalp potential of similar amplitude across perioral, supraorbital, and hand dorsum stimulation. In patients with facial neuropathic pain, CEP recording showed the selective damage of cold pathways providing complementary information to laser-evoked potential recording. Our clinical and neurophysiological study shows that this new device provides reliable information on trigeminal small fibres mediating cold sensation and might be useful for investigating patients with facial neuropathic pain associated with a distinct damage of cold-mediating fibres.