Normal pressure hydrocephalus: Neurophysiological and neuropsychological aspects: a narrative review.

ABSTRACT: Idiopathic normal pressure hydrocephalus (NPH) is a syndrome that affects elderly people and is characterized by excessive accumulation of cerebrospinal fluid in the brain ventricles. Diagnosis is based on the evaluation of clinical symptoms, which consists of a classic triad (Hakim triad), gait disturbances, cognitive impairment, and urinary incontinence. However, this complete triad is not always seen; therefore, it is difficult to make the diagnosis. NPH can be divided into primary or idiopathic NPH and secondary NPH. Diagnostic criteria for NPH remain a topic of discussion; however, the development of diagnostic techniques has brought new opportunities for diagnosis. The aim of this review is to present an overview of neurophysiological and neuropsychological approaches to support the clinical evaluation of patients with NPH and contribute to the differential diagnosis of NPH and dementia, as the clinical symptoms of NPH may resemble other neurodegenerative disorders.

The impact of the SARS-COV2 infection on the disorder of consciousness rehabilitation unit.

BACKGROUND AND OBJECTIVE: Disorders of consciousness include coma (cannot be aroused, eye remain closed), vegetative state-VS (can appear to be awake, but unable to purposefully interact) and minimally conscious state-MCS (minimal but definite awareness). The objective of this study is to assess the impact of the SARS-CoV-2 infection on the Disorder of Consciousness (DOC) Rehabilitation Unit. METHODS: This is a retrospective, longitudinal, descriptive, observational, pilot study. We consecutively enrolled 18 patients (age range: 40-72 years, 9 females and 9 males), from three to five months after a brain injury. They were grouped into VS (n = 8) and MCS (n = 10). A confirmed case of COVID-19 was defined as a positive result on high-throughput sequencing or real-time reverse-transcription polymerase chain reaction analysis of throat swab specimens. We collected data of lung Computed Tomography (CT) and laboratory exams. DOC patients who were positive for SARS-CoV-2 were classified into severe and no severe infected group, according to the American Thoracic Society guidelines. RESULTS: A total of 18 hospitalized patients with (16) and without confirmed (2) SARS-CoV-2 infection were included in the analysis. After one month, a follow-up clinical evaluation reported that one patient died, one patient was transferred from Covid Unit to Emergency Unit and 3 patients were resulted negative to double swab and they returned to Rehabilitative Unit. Significant differences were reported about hypertension, cardiac disease and respiratory problems between the patients with severe infection and patients without severe infection (P< 0.001). The laboratory findings, such as blood cell counts (P < 0.001), C-reactive protein, D-dimer, potassium and vitamin D levels, seemed to be considered as useful prognostic predictors. CONCLUSIONS: To our knowledge, this is the first longitudinal study on a sample of chronic DOC patients affected by SARS-CoV-2. This study may offer important new clinical information on COVID-19 for management of DOC patients. Our findings showed that for the subjects with severe infection due to COVID-19, rapid clinical deterioration or worsening could be associated with clinical and laboratory findings, which could contribute to high mortality rate. During the COVID-19 epidemic period, the clinicians should consider all the reported risk factors to avoid delayed diagnosis or misdiagnosis and to prevent the infection transmission in DOC Rehabilitation Unit.

Parosmia and Neurological Disorders: A Neglected Association.

Parosmia is a distorted olfactory sensation in the presence of an odor. This olfactory disorder can affect the quality of life of most patients who experience it. Qualitative olfactory dysfunctions, such as parosmia and phantosmia, may be clinical conditions secondary to neurological diseases. The incidence of parosmia is underestimated, as well as its association with neurological diseases, due to poor self-reporting of patients and lack of objective methods for its measure. In this paper, we show selected clinical cases of parosmia associated with neurological disorders, such as traumatic brain injury and multiple sclerosis. These clinical cases show how the correct diagnosis of parosmia can represent the tip of the iceberg of important underlying neurological disorders and be a good prognostic indicator of their progression or recovery.

Role of visual P300 in cognitive assessment of subacute stroke patients: a longitudinal study.

Aim: The aim of this study was to assess if pre- and post- event related potentials (ERPs) components after visual stimulation training admitted differences exist in subacute stroke patients and to observe the outcome markers of cognitive functions recovery by using Neurowave system.Materials and Methods: Eighteen ischemic subacute stroke patients were enrolled and underwent to neuropsychological evaluation and ERPs recording at two time points, at baseline (T0) and after 3 months from (T1). All patients were stimulated with customized images for three days a week.Findings: Intra group analysis showed a significance difference in ERPs parameters and neuropsychological tests. Correlation analysis showed a significant relation between neuropsychological and ERP values.Conclusion: Our findings confirm that P300 ERPs' component could be a predictive marker for cognitive recovery of ischemic subacute stroke patients. Intensive programs of neurosensory stimulation could facilitate recovery of cognitive and attentive functions in subacute cerebrovascular disease.

Recovery of malnutrition in a patient with severe brain injury outcomes: A case report.

RATIONALE: Severe brain injury often induces a state of malnutrition due to insufficient caloric and protein input. If left untreated, it will have a negative impact on rehabilitation. Nutritional therapy provides caloric and the nutritional support necessary to cover the daily needs and help contrast hospital infections. Our hypothesis is that integration of natural foods in the daily diet can enhance the recovery of the state of malnutrition and increase rehabilitation outcomes. PATIENT CONCERNS: We present the case of a young man with traumatic brain injury caused by a car accident. Who underwent tracheostomy and percutaneous endoscopic gastrostomy (PEG) procedures, had severe consciousness disorder, was severely malnourished and therefore underweight. DIAGNOSIS: He was severely underweight, malnourished, with a severe consciousness disorder that necessitated the tracheostomy and the PEG. INTERVENTIONS: Our approach included caloric implementation of artificial nutrition and the gradual introduction of semi-liquid natural foods administered through PEG. OUTCOMES: The patient was followed for a year during which the metabolic/nutritional pattern and the blood tests improved, normal weight restored, and consciousness regained. CONCLUSION: Nutritional intervention integrated with natural foods, has allowed a gradual increase in weight, a better recovery of the lean mass and the stabilization of the metabolic-nutritional framework.Nutritional approach used has contributed to the reduction of recovery times, making the therapeutic path more effective.

Olfactory event-related potentials in a functionally anosmic patient with arrested hydrocephalus.

Hydrocephalus is one of the lesser known causes of central olfactory loss. The pathogenesis of hydrocephalus involves the olfactory bulbs or tracts, and more rarely, other frontotemporal cortical regions. We describe a case of olfactory dysfunction in a macrocephalic 63-year-old female patient with arrested hydrocephalus. Her olfactory function was assessed by using the Sniffin' Sticks test, olfactory event-related potentials (OERPs), and 3-Tesla magnetic resonance imaging (MRI). An OERP examination suggested partial impairment of the central olfactory pathways and central parietal regions where OERP amplitude is maximal. Indeed, we found an evident olfactory potential trace with an increased latency only on Pz derivation. However, structural MRI showed important cortical brain thinning and large expansion of the third ventricle, with evident damage of the olfactory frontotemporal areas. The Sniffin' Sticks test and MRI supported the diagnosis of anosmia, while OERP findings indicated partial preservation of olfactory function, likely due to an adaptation of the central olfactory system. These findings highlight the importance of a multi-integrated approach to detect olfactory impairment.

Olfactory dysfunction as a prognostic marker for disability progression in Multiple Sclerosis: An olfactory event related potential study.

Multiple sclerosis (MS) is a chronic inflammatory disease and one of the leading causes of disability in young adults. Functional markers able to predict MS progression are still lacking. It is recognized that olfactory dysfunction may be an early symptom in MS. The aim of this study was to investigate whether alterations in olfactory event-related potentials could play a prognostic role in MS. Thirty patients affected by MS relapsing-remitting underwent an olfactory potential examination (T0). Three years after baseline (T1), 28 of 30 patients were clinically evaluated by expanded disability status scale. In addition, the number of Disease Modifying Therapies (DMTs) and the total number of relapses occurred in the last 3 years were collected. At T1, we observed a negative correlation between presence/absence of olfactory potentials and expanded disability status scale scores (rpb = -0.48; p = 0.009). A significant trend for a negative correlation between presence/absence of olfactory potentials and disease duration (rpb = -0.36; p = 0.06) and total number of relapses (rpb = -0.34; p = 0.08) was found. Only patients with olfactory potential absence showed a significant trend in the difference of the disability status scale (p = 0.06) between T0 and T1. In the sub-group of patients with reduced olfactory potential amplitude, we detected a trend for a negative correlation between the disability status scale and the amplitude of N1-P2 components more marked at T1 (r = -0.52; p = 0.06) than T0 (r = -0.47; p = 0.09). This is the first study that evaluated the prognostic role of olfactory event-related potentials in MS. Our results highlighted that olfactory alterations of MS patients were related to disability progression and, to a lesser extent, disease activity. The analysis of olfactory potential parameters confirmed the involvement in olfactory network damage of inflammatory and/or neurodegeneration processes which could predict the progressive course of the disease.

Functional MRI and laser-evoked potentials evaluation in Charcot-Marie-Tooth syndrome.

Charcot-Marie-Tooth (CMT) disease is a genetically heterogeneous group of disorders. Pain is a less common symptom complained by CMT patients. We described a case of a 39-year-old male patient affect by Charcot-Marie-Tooth (CMT) disease compared to five healthy controls (HC), to assess the sensory and the nociceptive pathways by using LEPs recording associated to fMRI examination, to find an "objective" marker which could be used in the management of CMT patient. The nociceptive system was evaluated by laser-evoked potentials (LEPs). Moreover, fMRI (functional magnetic resonance imaging) examination, by using laser stimuli, was performed. LEPs' examination showed an increase of latency and an amplitude reduction respect to HC. The laser stimulation during fMRI showed a decreased cortical activations if compared to HC. The originality of this paper, although limited to a single case, resides in a detailed evaluation of CMT1 patient performed by using neurophysiologic and neuroimaging methods to investigate extensively the sensory nociceptive pathways.

Techniques of cognitive rehabilitation in patients with disorders of consciousness: a systematic review.

Acquired brain injury can produce severe impairments of alertness, cognition, behavior, and, sometimes, an impairment of consciousness. Several studies defined the criteria to distinguish the different level of disorders of consciousness (DOC) and many tools to evaluate awareness, alertness, and response to stimuli were created. The aim of this review is to assess the advanced research of rehabilitative protocols and which rehabilitative techniques are used in the care of DOC patients.

Role of diffusion tensor imaging in the diagnosis and management of post-traumatic anosmia.

INTRODUCTION: Anosmia is a possible complication of Traumatic Brain Injury (TBI). Psychometric and electrophysiological methods of olfaction measure and Magnetic Resonance Imaging (MRI) are the tools to evaluate the post-traumatic olfactory loss. Diffusion Tensor Imaging (DTI) provides useful data for a better understanding of etiopathogenesis TBI-related anosmia, in particular the loss of neural connections and their eventual recovery over time. MATERIALS AND METHODS: This study describes a case of TBI-related anosmia. The olfactory function was evaluated by Sniffin' Sticks Test (SST), Olfactory Event-Related Potentials (OERPs), MRI and DTI at baseline (T0) and after one year (T1). RESULTS: At baseline, SST highlighted a functional anosmia. The OERPs showed the presence of a small N1-P2 complex. MRI confirmed the presence of a scarring involved in the right orbitofrontal cortex (OFC). DTI detected a reduction in the average length and the number of neuronal fibre pathways of right OFC. At T1, a recovery of olfactory function was confirmed by SST and OERPs. CONCLUSION: While MRI images are unchanged from T0, DTI showed an increase in average length and number of fibre tracts in the right OFC. DTI could be a valid tool to display a post-traumatic loss of neural connections and to better understand TBI-recovery mechanisms.

The Olfactory System Revealed: Non-Invasive Mapping by using Constrained Spherical Deconvolution Tractography in Healthy Humans.

Although the olfactory sense has always been considered with less interest than the visual, auditive or somatic senses, it does plays a major role in our ordinary life, with important implication in dangerous situations or in social and emotional behaviors. Traditional Diffusion Tensor signal model and related tractography have been used in the past years to reconstruct the cranial nerves, including the olfactory nerve (ON). However, no supplementary information with regard to the pathways of the olfactory network have been provided. Here, by using the more advanced Constrained Spherical Deconvolution (CSD) diffusion model, we show for the first time in vivo and non-invasively that, in healthy humans, the olfactory system has a widely distributed anatomical network to several cortical regions as well as to many subcortical structures. Although the present study focuses on an healthy sample size, a similar approach could be applied in the near future to gain important insights with regard to the early involvement of olfaction in several neurodegenerative disorders.

Effect of the antiepileptic therapy on olfactory disorders associated with mesial temporal sclerosis.

Parosmia has been described in neurological disorders, including temporal epilepsy. We reported a case of parosmia associated with unilateral hyposmia and mesial temporal sclerosis. We assessed the olfactory function by using Sniffin' sticks test and olfactory event-related potentials (OERPs). The findings of unilateral deficit of identification associated with parosmia only in the side ipsilateral to mesial temporal sclerosis area, that involves temporal olfactory regions responsible for higher level of smell processing, suggest a central genesis of olfactory disorders. The administration of levetiracetam restored olfactory function, OERP N1-P2 amplitude, and mesial temporal sclerosis-related electroencephalographic findings.

Neurophysiological assessment for evaluating residual cognition in vegetative and minimally conscious state patients: a pilot study.

The aim of this study was to assess residual cognitive function and perform outcome evaluation in vegetative state (VS) and minimally conscious state (MCS) patients, using Neurowave, a system able to monitor event-related potentials (ERPs) induced by neurosensory stimulation. Eleven VS and five MCS patients underwent neurological examination and clinical evaluation performed using validated clinical and behavioral scales; they also underwent neurosensory stimulation, which consisted of administration of target images (rare stimuli), relevant to the patient's personal history and having emotional significance, alternated with nontarget images ("standard" stimuli), which had no emotional significance. All simultaneous ERP responses at baseline (T0) and at three months from T0 (T1) were recorded. At T0 we found significant differences between the VS and MCS patients for the N200 (p=0.02) and P300 (p=0.04) waves. The neurophysiological analysis at T1 showed a significant difference only for P300 (p=0.02), probably due to the improvements observed in the VS subjects for the N100 (p=0.009) and N200 (p=0.02) sensory components. Neurophysiological assessment for evaluating residual cognition in vegetative and minimally conscious state patients: a pilot study Our findings seem to show the value of ERP monitoring in VS and MCS patients as a means of investigating residual cognitive function. This approach could guide early therapeutic and rehabilitation interventions, and contribute to identifying better diagnostic and prognostic markers for use in unresponsive or low-responsive patients.

Post-traumatic olfactory loss: psychophysical, electrophysiological and neuroradiological findings in three single case studies.

BACKGROUND: Traumatic brain injury is one of the main causes of smell disorders. The degree of olfactory loss may vary and depend on the severity, nature and location of injury within the olfactory system. The diagnosis of disorders of the sense of smell is based on medical history and clinical data supported by psychophysical tests of smell, electrophysiological and neuroimaging measures. METHODS: This study reports three single clinical cases of post-traumatic anosmia evaluated by Sniffin' Sticks Test, Olfactory Event-Related Potential and Magnetic Resonance Imaging examinations. RESULTS: The Olfactory Event-Related Potential findings confirmed the presence of functional olfactory impairment in all three post-traumatic patients showing a good correlation with results of the psychophysical testing. In particular, Sniffin' Sticks Test and OERPs allowed to demonstrate the functional nature of post-traumatic olfactory loss, while the MRI identified the location and extent of injury compatible with the olfactory disorder. CONCLUSIONS: OERPs may have a good clinical application in objective diagnosis of post-traumatic anosmia, especially when the neuroradiological examination does not show lesions compatible with olfactory loss.

Detection of olfactory dysfunction using olfactory event related potentials in young patients with multiple sclerosis.

BACKGROUND: Several studies reported olfactory dysfunction in patients with multiple sclerosis. The estimate of the incidence of olfactory deficits in multiple sclerosis is uncertain; this may arise from different testing methods that may be influenced by patients' response bias and clinical, demographic and cognitive features. AIMS: To evaluate objectively the olfactory function using Olfactory Event Related Potentials. MATERIALS AND METHODS: We tested the olfactory function of 30 patients with relapsing remitting multiple sclerosis (mean age of 36.03±6.96 years) and of 30 age, sex and smoking-habit matched healthy controls by using olfactory potentials. A selective and controlled stimulation of the olfactory system to elicit the olfactory event related potentials was achieved by a computer-controlled olfactometer linked directly with electroencephalograph. Relationships between olfactory potential results and patients' clinical characteristics, such as gender, disability status score, disease-modifying therapy, and disease duration, were evaluated. RESULTS: Seven of 30 patients did not show olfactory event related potentials. Sixteen of remaining 23 patients had a mean value of amplitude significantly lower than control group (p<0.01). The presence/absence of olfactory event related potentials was associated with dichotomous expanded disability status scale (p = 0.0433), as well as inversely correlated with the disease duration (r = -0.3641, p = 0.0479). CONCLUSION: Unbiased olfactory dysfunction of different severity found in multiple sclerosis patients suggests an organic impairment which could be related to neuroinflammatory and/or neurodegenerative processes of olfactory networks, supporting the recent findings on neurophysiopathology of disease.

Persistent anosmia in a traumatic brain injury patient: role of orbitofrontal cortex.

BACKGROUND: The olfactory loss due to traumatic brain injury is a common clinical condition. The understanding of the cortical areas involved in ability to detect, discriminate and identify the odours is still limited. However, it has been shown that the orbitofrontal cortex (OFC) is involved in the discrimination and recognition of odours and in particular the right OFC has a dominant role in the central processing of smell. METHOD: This study used the Sniffin' Sticks Test to evaluate olfactory function of a 40-year-old female with persistent post-traumatic anosmia and to have a objective measure method for the follow-up. RESULTS: A marked decrease in the ability to identify and discriminate odours was found. On the other hand the ability to perceive the odours was little compromised. A cerebral Magnetic Resonance Imaging, performed 10 months after the trauma, showed the presence of a post-traumatic scarring in the right frontal lobe involving the OFC. CONCLUSIONS: In this case of post-traumatic anosmia, the ability to perceive and recognize odours does not seem to be compromised in the same measure. It is postulated that the post-traumatic outcomes, involving areas of multisensory integration such as the OFC, have an important pathogenetic role in the loss of ability to recognize and discriminate odours.