Oxaliplatin-induced Acute Neurotoxicity Recovers Between Repeat Infusion Cycles: An Axonal Excitability Repeated Multiple Measurements Study.

Background/Aim: Oxaliplatin, a platinum-based chemotherapy used in the treatment of colorectal cancer, induces acute neurotoxicity following infusion. The aim of this study was to establish whether alterations in axonal excitability develop progressively with higher cumulative doses and whether there is a recovery in motor axons after each cycle of treatment. Patients and Methods: Twenty consecutive patients with a colorectal cancer diagnosis, referred from the Oncology Department of Aretaieion Hospital of Athens, were enrolled in this study between October 2018 and May 2019. None of the participants had diabetes, alcohol abuse, known neuropathy or were previously treated with another neo-adjuvant therapy. Threshold Tracking techniques and Qtrac software were used for assessing axonal excitability in motor axons. Excitability recordings were undertaken before and immediately after the end of oxaliplatin infusion. Results: Statistically significant changes were found (p<0.01) in axonal excitability (relative refractory period, refractoriness at 2 ms and 2.5 ms, sub-excitability and super-excitability) before and after oxaliplatin infusion. No statistically significant changes (p>0.05) were found in threshold electrotonus and strength-duration parameters before and after oxaliplatin infusion. We also did not find statistically significant differences (p>0.05) between means of excitability parameters before infusion at each cycle. Conclusion: Our study confirms oxaliplatin-induced acute neurotoxicity following infusion and suggests that motor axons recover between repeat infusion cycles.

Parainfectious Brown-Sequard syndrome associated with Mycoplasma pneumoniae in an adult patient: a case report.

INTRODUCTION: Acute transverse myelitis (ATM) refers to a rare severe acquired spinal cord inflammation, with a challenging diagnostic work-up and treatment. CASE PRESENTATION: We report the case of a 42-year-old patient who presented with loss of temperature and pain sensation beneath the C5 dermatome in her left side and reported a history of a possible respiratory tract illness 10 days ago. Within 2 days, clinical worsening was noted, compatible with Brown-Sequard syndrome. Spinal magnetic resonance imaging revealed a T2 sequence abnormal signal from level C4 to T3 and cerebrospinal fluid (CSF) studies showed only a mild pleocytosis mononuclear type. Extensive CSF and blood tests revealed only high Mycoplasma pneumoniae IgM and IgG titers. Treatment with high-dose intravenous methylprednisolone and oral azithromycin were administrated and the patient recovered completely within two months. DISCUSSION: We would like to highlight the importance for physicians to consider M. pneumoniae in their differential diagnosis as a potential cause when encountering patients with symptoms of ATM and inflammatory Brown-Sequard syndrome.

Peduncular hallucinosis associated with pontine hemorrhage in an adult patient.

Peduncular hallucinosis refers to a rare neurophychiatric disorder presenting with vivid visual hallucinations, disturbances of sleep, and oculomotor dysfunction. It is typically caused by mesencephalic lesions. Nonetheless, a few cases have also been reported, in which the same syndrome was associated with thalamic and pontine lesions. We report the case of a 63-year-old male patient presenting to the Emergency Department of our hospital with irritability, gait difficulty, and diplopia of sudden onset two hours ago. Neurological examination revealed dysarthria, right facial palsy, bilateral gaze palsy, dysmetria of his left extremities, left-sided hemihypaethesia and extensory plantar response on the left. Brain computerized tomography (CT) showed a hemorrhagic lesion on the right lateral side of the pons. During his hospitalization at the Department of Neurology, he developed visual hallucinations, confusion, disorientation, insomnia, and strong emotional response. An extensive laboratory screening was performed and showed no abnormal findings. Suspecting peduncular hallucinosis due to the brainstem lesion, treatment with quetiapine and melatonin was administered to the patient and symptoms resolved completely within days. Subsequently, gradual neurological clinical improvement was also noted and two weeks after his admission, a repeated brain CT and a brain magnetic resonance imaging (MRI) showed partial absorption of the brainstem hemorrhage. The patient underwent rehabilitation for two months, showing further clinical improvement, and treatment with quetiapine and melatonin was discontinued without any further episodes being noted. A repeated brain MRI was performed two months after his admission to our hospital and showed no hemorrhage, but a mixed signal intensity core and a hypointense hemosiderin rim at the location of the absorbed hemorrhagic lesion, compatible with pontine carvenoma. Peduncular hallucinosis is most commonly associated with ischemic lesions of the posterior brain blood circulation, but different lesions have been reported, like vasospasm, brain tumors, encephalitis, hemorrhage associated with vascular malformations, such as a carvenoma, as seen in our case, representing a very rare form of peduncular hallucinosis.

Primary angiitis of the central nervous system in a patient with transient episodes of headache and aphasia: A case report.

Primary angiitis of the central nervous system (PACNS) refers to a rare form of vasculitis of unknown cause, with a challenging diagnostic work-up. We report the case of a 57-year-old patient who presented with transient episodes of headache and global aphasia. Cerebrospinal fluid (CSF) examination revealed lymphocytic pleocytosis with moderate elevated protein and normal glucose. CSF and serum tests for infections and autoimmune/paraneoplastic antibodies were negative, except CSF polymerase chain reaction testing that detected Epstein-Barr virus (EBV). Magnetic resonance imaging of the brain with intravenous gadolinium showed meningeal enhancement and pachymeningitis. Due to continuous relapsing episodes of aphasia, a leptomeningeal and brain tissue biopsy was performed and revealed lesions of granulomatous necrotising vasculitis of medium-sized leptomeningeal and intracranial vessels, as well as negative in situ hybridism for EBV. A diagnosis of primary granulomatous necrotising angiitis of the central nervous system was made, and the patient was treated with intravenous methylprednisolone and oral cyclophosphamide, showing excellent response to treatment. Diversity in clinical and laboratory features makes it difficult for PACNS to be distinguished by other systemic vasculitides. Laboratory tests and neuroimaging can provide guidance in evaluation of the patients and exclude other possible causes, but tissue biopsy remains the gold standard for a definite diagnosis.

Pure small fiber neuropathy in alcohol dependency detected by skin biopsy.

BACKGROUND: Alcohol overconsumption is well known to cause damage to the peripheral nervous system. The aim of this study was the functional and structural evaluation of the small nerve fibers in alcohol-dependent subjects, with or without symptoms of peripheral neuropathy. METHODS: Twenty-six consecutive alcohol-dependent subjects treated for detoxification voluntarily in the specialized unit of the Athens University Psychiatric Clinic were enrolled in this prospective study over 18 months. Every subject was assessed by peripheral nerve evaluation using the Neuropathy Symptoms Score (NSS) and Neuropathy Impairment Score (NIS), followed by nerve conduction studies (NCS), quantitative sensory testing (QST), and skin biopsy. Twenty-nine normal subjects, age- and gender-matched, constituted the control group. RESULTS: Peripheral neuropathy was diagnosed in 16 subjects (61.5%). Among these 16 subjects, pure large fiber neuropathy (LFN) was found in two subjects (12.5%), pure small fiber neuropathy (SFN) was found in eight subjects (50%), and both large and small fiber neuropathy was diagnosed in six patients (37.5%). The intraepidermal nerve fiber density (IENFD) of the patients' skin biopsy was significantly lower than that of the control group. Additionally, QST results showed a statistically significant sensory impairment in the patients. CONCLUSIONS: Our study confirms small fiber neuropathy due to alcohol abuse with a high prevalence of pure SFN that might have remained undetected without QST and IENFD.