Mild traumatic brain injury from primary blast vs. blunt forces: post-concussion consequences and functional neuroimaging.

INTRODUCTION: Primary blast forces may cause dysfunction from mild traumatic brain injury (mTBI). OBJECTIVE: To investigate the effects of primary blast forces, independent of associated blunt trauma and post-traumatic stress disorder, on sensitive post-concussive measures. METHODS: This study investigated post-concussive symptoms, functional health and well-being, cognition, and positron emission tomography (PET) neuroimaging among 12 Iraq or Afghanistan war veterans who sustained pure blast-force mTBI, compared to 12 who sustained pure blunt-force mTBI. RESULTS: Both groups had significantly lower scores than published norms on the Rivermead Post-Concussion Questionnaire (RPQ) and the SF36-V Health Survey. Compared to the Blunt Group, the Blast Group had poorer scores on the Paced Auditory Serial Addition Test (PASAT) and greater PET hypometabolism in the right superior parietal region. Only the Blast Group had significant correlations of their RPQ, SF36-V Mental Composite Score, and PASAT scores with specific regional metabolic changes. CONCLUSION: This pilot study suggests that pure blast force mTBI may have greater post-concussive sequelae including deficits in attentional control and regional brain metabolism, compared to blunt mTBI. A disturbance of a right parietal-frontal attentional network is one potential explanation for these findings.

Changes in personality after mild traumatic brain injury from primary blast vs. blunt forces.

INTRODUCTION: Injuries from explosive devices can cause blast-force injuries, including mild traumatic brain injury (mTBI). OBJECTIVE: This study investigated changes in personality from blast-force mTBI in comparison to blunt-force mTBI. METHODS: Clinicians and significant others assessed US veterans who sustained pure blast-force mTBI (n = 12), as compared to those who sustained pure blunt-force mTBI (n = 12). Inclusion criteria included absence of any mixed blast-blunt trauma and absence of post-traumatic stress disorder. Measures included the Interpersonal Measure of Psychopathy (IM-P), the Big Five Inventory (BFI), the Interpersonal Adjectives Scale (IAS) and the Frontal Systems Behaviour Scale (FrSBe). RESULTS: There were no group differences on demographic or TBI-related variables. Compared to the Blunt Group, the Blast Group had more psychopathy on the IM-P, with anger, frustration, toughness and boundary violations and tended to more neuroticism on the BFI. When pre-TBI and post-TBI assessments were compared on the IAS and FrSBe, only the patients with blast force mTBI had become more cold-hearted, aloof-introverted and apathetic. CONCLUSION: These results suggest that blast forces alone can cause negativistic behavioural changes when evaluated with selected measures of personality. Further research on isolated blast-force mTBI should focus on these personality changes and their relationship to blast over-pressure.

The neuropsychiatric manifestations of Huntington's disease-like 2.

Huntington's disease-like 2 (HDL2) is a rare neuropsychiatric disorder that resembles HD but results from a distinct mutation. The authors present a patient with HDL2, hospitalized for psychiatric management, and they review the neuropsychiatric manifestations of this disorder. Depression, irritability/aggression, and frontal lobe personality changes are common presentations of HDL2 and are comparable to classic HD. Patients with HDL2 may differ from those with HD in having a lower incidence of obsessive-compulsive acts, known suicides, antisocial acts, and changes in sexuality. Clinicians should be aware of the psychiatric presentations of this disorder, when to obtain genetic testing, and how to manage problematic behaviors.

Chronic epileptic encephalopathy in adult patients with bilaterally synchronous frequent and/or prolonged subclinical epileptiform discharges.

We followed four patients with infrequent convulsive seizures for four to 10 years, with periodic EEGs and neuropsychological tests. All four had bursts of frontally predominant, bilaterally synchronous 1.5-3-Hz spike or polyspike and slow-wave discharges (SWDs) that initially comprised 15% to 88% but were reduced to 5% or less of total EEG time with appropriate antiepileptic drugs. Case 1 showed a 30-point improvement in his verbal WAIS-R score and Case 4 a 21-point improvement in his performance WAIS-R score, over nine- and five-year periods, respectively, with normalization of frontal executive function. Cases 2 and 3 showed no improvement in frontal executive dysfunction despite being free of SWDs for nine and five years, respectively. These patients had variable degrees of epileptic encephalopathy and subclinical SWDs. They illustrate the importance of minimizing the occurrence of SWDs with appropriate antiepileptic drugs and long-term monitoring with neuropsychological tests because chronic cognitive deficits are potentially reversible.

Frontal-executive versus posterior-perceptual mental status deficits in early-onset dementias.

BACKGROUND: Compared to late-onset dementias, early-onset dementias (EODs) may have greater focal cognitive involvement with differences in frontal-executive compared to posterior-perceptual deficits. OBJECTIVE: This study evaluated whether mental status screening based on this frontal-posterior axis can distinguish EODs. METHODS: Twenty-three patients each with early-onset Alzheimer's disease (eAD), frontotemporal dementia (FTD), or subcortical ischemic vascular disease (SIVD), and 20 normal controls underwent the Frontal Assessment Battery (FAB) and the Perceptual Assessment Battery (PAB). RESULTS: Compared to controls, SIVD and FTD groups were impaired on the FAB whereas eAD and SIVD groups were impaired on the PAB. The FAB/PAB ratio further differentiated the groups (F(3,85) = 26.49, P < .001). For sensitivities and specificities of 93%, a cut-off score of 1.25 on the FAB/PAB distinguished eAD, and a cut-off of 0.83 distinguishing FTD. CONCLUSION: Although preliminary, this study indicates that mental status screening based on frontal versus posterior cortical functions may help clinicians diagnose EODs.

"Denkfaulheit" in frontotemporal dementia: a preliminary analysis.

The initial recognition of frontotemporal dementia is often difficult. Frontotemporal dementia presents with subtle personality changes in the absence of a definitive biomarker. The authors report an analysis of cognitive shallowness, or "Denkfaulheit," in patients with frontotemporal dementia early in its course.

Changes in dietary or eating behavior in frontotemporal dementia versus Alzheimer's disease.

BACKGROUND: Changes in dietary or eating behavior are common in dementia and may help distinguish between different dementing illnesses. OBJECTIVE: To evaluate and characterize differences in dietary and eating behavior among patients with early frontotemporal dementia (FTD) versus Alzheimer's disease (AD). METHODS: This study administered the Food-Related Problems Questionnaire (FRPQ) to caregivers of 16 patients with FTD and 16 comparable patients with AD. The FRPQ was evaluated at initial presentation when patients presented for a diagnostic evaluation. RESULTS: Compared with the AD patients, the FTD patients had significantly more changes on the FRPQ. Subscale analysis indicated that the FTD patients showed impairment of observed satiety, improper taking of food, and inappropriate responses when food was not available. CONCLUSIONS: The use of food-related questionnaires, such as the FRPQ, can help distinguish FTD patients, early in their course, from those with AD and can further characterize the altered dietary and eating behavior.

Psychotic symptoms in frontotemporal dementia: prevalence and review.

BACKGROUND/AIMS: Although most patients with frontotemporal dementia (FTD) present with neuropsychiatric symptoms, the frequency of psychotic symptoms is unclear. This study aims to determine the prevalence of psychotic symptoms in a large cohort of well-diagnosed and followed FTD patients compared to age-matched patients with Alzheimer's disease (AD) and to further review the literature on psychosis in FTD. METHODS: Delusions, hallucinations and paranoia were evaluated among 86 patients who met consensus criteria for FTD, had frontotemporal changes on functional neuroimaging and were followed for 2 years. They were compared to 23 patients with early-onset AD on a caregiver-administered psychiatric questionnaire. RESULTS: Among the FTD patients, only 2 (2.3%) had delusions, 1 of whom had paranoid ideation; no FTD patient had hallucinations. This was significantly less than the AD patients, 4 (17.4%) of whom had delusions and paranoia. Other investigations fail to establish a significant association of psychosis with FTD. CONCLUSIONS: These findings, and a literature review, indicate that psychotic symptoms are rare in FTD, possibly due to limited temporal-limbic involvement in this disorder.

Cognitive differences between early- and late-onset Alzheimer's disease.

Although neuropathologic studies showed that early-onset Alzheimer's disease (EAD) and "senile dementia" were indistinguishable, clinical studies suggested that EAD and late-onset Alzheimer's disease (LAD) were cognitively distinct. We sought to investigate whether EAD and LAD are cognitively different by comparing patients at the extremes of the ages of onset in order to maximize features that might separate them. We compared 44 men with EAD (age of onset less than 65 years) with 44 men with LAD (age of onset 84 years or older) on an intake cognitive screening examination on initial presentation. The EAD and LAD groups did not differ on dementia or most cognitive variables. Compared with EAD, the LAD group had worse verbal fluency and motor-executive functions. These differences disappeared when age differences were taken into account. We conclude that Alzheimer's disease is a clinically heterogeneous disorder whose manifestations can vary with age of onset. These differences indicate age-related vulnerabilities in this disease.

Children with ESES: variability in the syndrome.

OBJECTIVE: We undertook a retrospective study of children who present with significant activation of paroxysmal discharges during sleep to examine the clinical spectrum of disorders that present with such an EEG abnormality. BACKGROUND: Electrical status epilepticus in sleep (ESES) is an electrographic pattern characterized by nearly continuous spike-wave discharges in slow wave sleep, usually with a frequency of 1.5-3 Hz and usually diffuse and bilateral in distribution. A variety of neurocognitive and behavioral problems have been associated with this EEG pattern. METHODS: We conducted a retrospective review of 1497 EEG records of patients admitted to University of California, Los Angeles (UCLA) for overnight video-EEG monitoring during a 5 year interval. Demographic, clinical and electroencephalographic variables were evaluated. RESULTS: EEG records for 102 patients meeting criteria were identified. Clinical information was available for 90 of those patients. Eighteen of these patients could be diagnosed with Landau-Kleffner syndrome (LKS). Key findings include: (1) neuroimaging abnormalities were uncommon in our LKS patients; (2) among children who do not fit the specific diagnostic criteria for LKS, a spike-wave index (SWI) >50% was more likely to be associated with global developmental disturbances than SWI < or =50% (p<0.05); (3) Children with generalized discharges were more likely to experience severe or global developmental disturbance than those with focal abnormalities, without reaching statistical significance (p=0.07). CONCLUSIONS: Severity of ESES can vary over time between and within patients and clinical status does not always directly correlate with SWI. However, the prognosis of LKS is substantially better than CSWS and these two disorders could be classified in a dichotomous manner rather than be seen as two points along a continuum.

Chronically Impaired Frontal Lobe Function from Subclinical Epileptiform Discharges.

Subclinical epileptiform discharges (SEDs) are a common occurrence on electroencephalograms (EEGs). Their potential for acutely disrupting cognitive functions has been well documented, but detailed studies of cognitive performance by patients with chronic exposure to disruptive SEDs have been lacking and scant data have been available to guide treatment decisions or to assist in predicting recovery. We identified a patient with frequent frontotemporally (FT) predominant SEDs and monitored cognitive performance over time with periodic neuropsychological testing and EEGs. Over a 16-year period, Full Scale IQ rose 23 points and Verbal IQ rose 30 as SEDs were suppressed. Severity of impairment, reflected by the marked increase in cognitive performance over time, was not predicted by his appearance and performance on routine tests of cognitive functions in the clinic. Quantitating total SED duration per EEG provided an objective marker to track severity over time. The cumulative effects of chronic exposure to disruptive SEDs may create a sustained "cognitive burden" or encephalopathic state that persists even in the absence of ongoing discharges.