Reducing the rate of misdiagnosis in patients with chronic disorders of consciousness: Is there a place for audiovisual stimulation?

BACKGROUND: The patients with chronic Disorders of Consciousness (DoC) mostly present with extremely challenging differential diagnosis. The advanced analysis of electroencephalographic (EEG) signals induced by brain stimulation paradigms may provide an appropriate approach to differentiate patients with DoC, besides the clinical assessment. OBJECTIVE: This study was performed with an objective of identifying residual brain network perturbations following an innovative, non-invasive audiovisual stimulation protocol, which could be related to behavioral responsiveness in patients with DoC. METHODS: The study comprised of ten healthy controls (HC), seven patients with Minimally Conscious State (MCS), and nine patients with Unresponsive Wakefulness Syndrome (UWS). Both synchronous as well as asynchronous transorbital and transauricolar alternating current were employed as stimuli and their effects were measured in terms of functional and effective connectivity. RESULTS: A more noticeable deterioration of long range connectivity patterns were found in patients with UWS than in those with MCS, with an exception of two patients with UWS, who showed connectivity values similar to those of MCS patients. CONCLUSION: The audiovisual stimulation paradigm used in the present study may be employed as a supportive bedside tool for improving the differential diagnosis in patients with DoC.

Twist and turn into chronic disorders of consciousness: Potential role of the auditory stapedial reflex.

BACKGROUND: Patients suffering from chronic disorders of consciousness (DOC), including minimally conscious state (MCS) and unresponsive wakefulness syndrome (UWS), typically show an awareness impairment paralleled by a significant reflex hyper-excitability, which depend on the cortical deafferentation following brain-damage-induced thalamocortical system deterioration. Nonetheless, recent studies have shown a residual preservation of cortico-subcortical pathways that may sustain residual fragments of awareness in some DOC patients. OBJECTIVE: The aim of our study was to assess whether the cortical modulation of auditory stapedial reflex (ASR) could be a marker of a higher degree of brain network connectivity, which is a fundamental prerequisite for awareness generation and maintenance. METHODS: We applied a repetitive transcranial magnetic stimulation (rTMS) protocol over the primary auditory area and measured the neuromodulation effects on ASR threshold (ASRt) in a DOC sample and a healthy control group (HC). RESULTS: We observed an ASRt reduction in all the HC and MCS individuals, in parallel to a better sound-induced motor responsiveness in MCS sample, while all the UWS patients, but two, did not show any significant ASRt modulation. CONCLUSION: We hypothesize that our conditioning protocol may have entrained and potentiated some spared cortico-subcortical networks that sustained the clinical and electrophysiological amelioration we found. Our data electrophysiologically demonstrate for the first time that primary the auditory area can influence ASR elicitation, and such finding may support the DOC differential diagnosis.

Identification of a neck lump as a lymph node metastasis from an occult contralateral papillary microcarcinoma of the thyroid: key role of thyroglobulin assay in the fine-needle aspirate.

BACKGROUND: Thyroglobulin (Tg) assay of material from fine-needle aspiration of neck masses can help distinguish neck masses of thyroid origin from other masses. We describe its utility in a patient with an unusual constellation of findings, a neck lump identified as a lymph node metastasis from a contralateral occult papillary thyroid carcinoma (PTC). SUMMARY: A 56-year-old woman was referred to our center for evaluation of a 15-mm right lateral cervical neck mass which was strongly hypoechoic, not homogenous and contained several microcalcifications. There was no family history of thyroid disease, the patient was euthyroid and was not taking medications for thyroid disorders. On physical examination the thyroid was slightly enlarged and was normal on ultrasound except for a 1 x 3 mm hypoechoic nodule in the middle of the left lobe. Ultrasound-guided fine-needle aspiration biopsy (FNAB) of the right lateral cervical mass was performed with the Tg concentration of the FNAB washout liquid being >300 ng/mL and the cytology showing lymphoid elements mixed with polymorphous epithelial cells with atypical nuclei, suggesting lymph node metastasis from a cancer of epithelial origin. A lymph node metastasis from a papillary thyroid microcarcinoma (micro-PTC) was the presumptive diagnosis with the preoperative staging being Tx N1b. The patient underwent total thyroidectomy and bilateral lymph node dissection. At pathology, the right cervical mass was confirmed as lymph node metastasis of a PTC, and a unifocal micro-PTC was found in the middle left lobe. The patient was readmitted for a therapeutic (131)I dose (4810 MBq). At the time of (131)I administration, the whole-body scan showed only minimal thyroid bed uptake and serum Tg was <1 ng/mL. She was maintained on l-thyroxine treatment (150 microg/d). Five year later she did not have evidence of recurrent or residual PTC. CONCLUSIONS: We describe the first case of contralateral lymph node metastasis from a unifocal micro-PTC identified by the detection of high Tg levels in the wash-out liquid of FNAB.