Cases of two patients whose food aversions disappeared following severe traumatic brain injury

Role for Histone Deacetylation in Traumatic Brain Injury-Induced Deficits in Neuropeptide Y in Arcuate Nucleus: Possible Implications in Feeding Behavior

INTRODUCTION

Repeated traumatic events result in long-lasting neuropsychiatric ailments, including neuroendocrine imbalances. Neuropeptide Y (NPY) in the arcuate nucleus (Arc) is an important orexigenic peptide. However, the molecular underpinnings of its dysregulation owing to traumatic brain injury remain unknown.

METHODS

Rats were subjected to repeated mild traumatic brain injury (rMTBI) using the closed head weight-drop model. Feeding behavior and the regulatory epigenetic parameters of NPY expression were measured at 48 h and 30 days post-rMTBI. Further, sodium butyrate (SB), a pan-histone deacetylase (HDAC) inhibitor, was administered to examine whether histone deacetylation is involved in NPY expression post-rMTBI.

RESULTS

The rMTBI attenuated food intake, which was coincident with a decrease in NPY mRNA and protein levels in the Arc post-rMTBI. Further, rMTBI also reduced the mRNA levels of the cAMP response element-binding protein (CREB) and CREB-binding protein (CBP) and altered the mRNA levels of the various isoforms of the HDACs. Concurrently, the acetylated histone 3-lysine 9 (H3-K9) levels and the binding of CBP at the NPY promoter in the Arc of the rMTBI-exposed rats were reduced. However, the treatment with SB corrected the rMTBI-induced deficits in the H3-K9 acetylation levels and CBP occupancy at the NPY promoter, restoring both NPY expression and food intake.

CONCLUSIONS

These findings suggest that histone deacetylation at the NPY promoter persistently controls NPY function in the Arc after rMTBI. This study also demonstrates the efficacy of HDAC inhibitors in mitigating trauma-induced neuroendocrine maladaptations in the hypothalamus.

Post-traumatic taste disorders: a case series

Since 1800s there are reports of post-traumatic anosmia, but few studies investigated post-traumatic gustatory deficit and adopted validated evaluation tests. Peripheral and/or central mechanisms may be involved in the genesis of post-traumatic gustatory dysfunction. Beyond a reduction/loss (hypogeusia/ageusia) of gustatory function following a trauma, qualitative taste changes (dysgeusia) may occur. Especially when persistent, taste deficits might be particularly relevant for patient's quality of life and activities of daily life, but knowledge on this topic is limited. Fifty-three consecutive patients with previous head trauma were recruited. Every patient underwent a careful history taking and thorough olfactory and gustatory chemosensory testing by Sniffin'Sticks Extended test, Whole Mouth Test and Taste Strips Test. All patients had olfactory abnormalities (hyposmia: n = 10, functional anosmia: n = 43), while 10 of them (19%) showed taste deficits (dysgeusia: n = 3, dysgeusia with hypogeusia: n = 1, hypogeusia: n = 5, ageusia: n = 1). Here, we report clinical and neuroimaging data and detailed description of four meaningful cases representing central and peripheral injury patterns. Chemosensory evaluation might be useful to explore taste disorder, a still neglected and underestimated sequela of head trauma.

Changes in weight after traumatic brain injury in adult patients: a longitudinal study

BACKGROUND & AIMS

Although changes in weight have been reported after traumatic brain injury (TBI), their frequency and underlying factors are little known. Our aim was to determine the prevalence of weight changes and the associated factors during the recovery phase after TBI.

METHODS

Longitudinal follow-up of adults with TBI. Multivariate analysis was carried out on weight change, demographic data, dysexecutive syndrome, eating behavior, physical activity, therapeutic classes and metabolic complications.

RESULTS

107 patients (81 males/26 females), age 36 ± 13 yrs, baseline BMI 23.3 ± 3.9, followed for 38 (8-66) months, were included. In intensive care, patients lost a mean 11 ± 6 kg. End of follow-up, mean BMI was not different to pre-TBI BMI, but patients could be categorized in 3 groups: stable (30%), loss (28%, -8 ± 7 kg) and gain (42%, +9 ± 6 kg). Sex, age, severity of TBI, intensive care weight loss, physical activity, therapeutic classes and the occurrence of metabolic syndrome did not differ between the groups. Factors related to weight gain were hyperphagia, OR 4.5 (IC95%, 1.6-12.1) and presence of a dysexecutive syndrome, OR 2.5 (IC95%, 1.03-6.3). Factors related to weight loss were hypophagia, OR 4.1 (IC95%, 1.5-10.9) and higher pre-TBI BMI, OR 4.9 (IC95%, 1.7-14.0).

CONCLUSIONS

Over a median period of 38 months, 42% of TBI patients gained and 28% lost weight. Factors associated with these changes were the presence of a behavioral dysexecutive syndrome for weight gain, oral food intake and initial BMI, which were inversely associated with weight at end of follow-up. These findings highlight the importance of evaluating the time course of weight changes and providing specific nutritional care.