**6. Frontotemporal dementia**

PIB-PET is very useful in the differential diagnosis between iNPH and AD. Kondo et al. have demonstrated that 3 of 10 (30%) patients with iNPH without any clinical signs of AD had obvious cortical retention in PIB-PET, indicating that iNPH is one of the PIB-positive diseases [104].

In 2016, several studies on iNPH were published in the medical literature [105]. Below, inter-

There is no standardization of care or differentiation between various types of hydrocephalus

The most common complication seen in postshunting surgery is subdural hematoma, and it

Remarkable improvements in gait and clinical outcome are seen in patients presenting iNPH

After 6 months of shunt surgery in patients presenting iNPH, the best test for identifying

Some authors have demonstrated that the vascular brain expansion (during cardiac cycle) is quickly compensated by CSF volume flush, toward the spinal compartment due to a decreased spinal canal compliance, a decreased vascular brain expansion, or an increase of

Based on the knowledge that venous drainage helps to control intracranial pressure, some authors have highlighted the potential role of the right side of the heart and the jugular vein

In iNPH, the main goal of shunt therapy is to improve the patient's mobility and a mean

Dr. Hakim described the iNPH for the first time in 1964, but its physiopathology was not satisfactorily elucidated as yet. Although changes seen on the brain parenchymal after shunt surgery have not been documented, it seems to be that a number of patients with cerebral

At the present moment, reliable biomarkers for selection of iNPH patients for shunt therapy and T-tau or Aβ-42 for predicting shunt responsiveness are not available and need to be identified. Nevertheless, some potential microRNA biomarkers in the CSF are useful to differentiate iNPH patients from other presenting overlapping symptoms of other disorders such as

In iNPH patients, the endoscopy third ventriculostomy is also a choice of treatment although

Ventriculoatrial shunt (VAS) is another choice of treatment of iNPH, and some authors recommend it as a first choice because it is more physiological, no cardiopulmonary complications

A possible genetic component involved in the pathogenesis of iNPH may be present.

some authors have found that it is not effective in treatment of iNPH [106, 107].

have been reported, and less shunt malfunction in the follow-up is found.

ested readers can find a summary from the most relevant conclusions.

among the confirmed cases of hydrocephalus in the Middle East.

shows reduced and even worsening of gait in iNPH.

clinical improvements is the European-iNPH scale.

valves in the physiopathology of the intracranial pressure.

atrophy could be presenting a reversible subarachnoid augmentation.

subarachnoid space resistance to CSF flow.

improvement of 0.4 mph has been confirmed.

AD, PD, and progressive supranuclear palsy.

after shunting surgical procedures.

202 Cognitive Disorders

Frontotemporal dementia (FTD) is a common neurodegenerative disease associated with progressive atrophy of the frontal and temporal lobes, leading to changes in personality, behavior, and/or speech and language disorder. FTD is less common than the before-mentioned dementias. Among these clinical presentations, Pick's disease is the most common type of presentation due to damage on the frontal and temporal lobes characterized by behavior and personality (apathy) disorders, which usually precede memory loss and dysarthria.

Canu et al. [128] reported some multiparametric MRI findings useful to differentiate early onset of AD (EOAD) from BvFTD based on the cortical thinning of the precuneus, posterior cingulate, superior and inferior parietal lobe, supramarginal, postcentral, and lingual gyri, and lateral occipital cortex bilaterally, and the left rostral and caudal middle frontal gyri seen in EOAD. Compared with the control group, the authors found a widespread pattern of cortical thinning involving all cerebral lobes, and compared to EOAD, BvFTD patients showed cortical thinning on the lateral orbitofrontal gyrus and temporal pole bilaterally, right entorhinal cortex, and right medial orbitofrontal gyrus. A severe cortical involvement is suggestive of

Updated Information on Some Cognitive Disorders http://dx.doi.org/10.5772/intechopen.81826 205

Wernicke encephalopathy and Korsakoff syndrome [Wernicke-Korsakoff syndrome (WKS)] and alcohol-related dementia (ARD) are preventable, life-threatening neuropsychiatric syndromes resulting from thiamine deficiency mainly in patients with chronic alcoholism, anorexia nervosa or patients who have undergone bariatric surgery for obesity, chronic hepatic disease, immunodeficiency syndromes, nutritional deficiencies of any cause, metastatic carcinomas, hyperthyroidism, prolonged parenteral nutrition, hyperemesis gravidarum, longterm dialysis and diuretic therapy, among other causes, and clinically, patients' complaints

In most of our patients, WKS is an acute nutritional disorder characterized by the clinical triad of ophthalmoplegia, cerebellar disorder, and altered mental state secondary to neuronal loss and hemorrhagic lesions in the periaqueductal gray matter of the midbrain, the anterior

Altered mental state includes abulia, inattentiveness, and progressive memory disturbance with progressive deterioration of level of consciousness until comatose state if no treatment

Before ophthalmoplegia is established, the eye movement abnormalities begin with limita-

All patients presenting thiamine deficiency improve their symptoms rapidly when thiamine is replaced in a timely fashion. Sometimes, patients do not improve completely, and nystagmus, broad-based gait, and cognitive dysfunction including a selective amnestic disorder

Some authors said that during the acute symptomatic stage of Wernicke encephalopathy, there is an impairment of the glucose and oxidative cellular energy metabolism, leading to an imbalance of the ionic gradients across the cell membrane causing cytotoxic edema (intracellular water shift and cell injury) and vasogenic edema because of breakdown of the blood-brain barrier permeability with intravascular fluids penetrating into cerebral parenchymal [102]. Currently, it is well known that the MRI findings of cytotoxic or vasogenic edema are a remarkable information to detect WE in clinical settings and the presence of bilateral

tions of abduction or horizontal gaze, and gait ataxia progresses to inability to stand.

EOAD, while a prominent white matter damage might be indicative of bvFTD.

**7. Wernicke-Korsakoff syndrome and alcohol-related dementia**

about short-term memory, confusional states, and neuropsychiatry manifestations.

thalamus, and hypothalamus.

(Korsakoff syndrome) remain present.

is received.

Sometimes, clinical manifestations such as behavioral and personality changes, psychomotor slowness, and decline in executive functions can be seen in both iNPH and behavioral FTD (BvFTD) at the same time and indistinctly [110], and other neuropsychiatric symptoms are frequently detected in both diseases [111, 112] including mania, aggression, disturbances of impulse control, obsessive-compulsive disorder, and psychosis, including paranoia and hallucinations [113–115]. It is well known that personality changes, impulsive behavior, apathy, decreased social interest, and executive dysfunctions, including impairment in solving problems and inhibitory control, are typical manifestations of BvFTD [116]. Almost one-half of patients with frontotemporal lobe degeneration (FTLD) have a familial component, and some authors have found mutations in microtubule-associated protein tau, progranulin, and expanded hexanucleotide repeat in a noncoding region of the chromosome 9 open reading frame 72 (C9ORF72) as a common cause of the problem [117]. The expansion of C9ORF72 as a major genetic cause of FTLD has been confirmed by others [118]. On the other hand, Majounie et al. [119] reported that the C9ORF72 repeat expansion is the highest in Finland and is present in about 48% of familial FTLD.

Amyotrophic lateral sclerosis (ALS) is the most common motor presentation associated with the *C9ORF72* expansion, but extrapyramidal symptoms have also been documented [120–122]. Fifty percent of patients with ALS exhibit frontal executive deficits during the course of their disease representing the comorbidity of FTD-ALS and associated delusional disorder.

To distinguish BvFTD from iNPH can be a very difficult task considering that both have similar clinical manifestations. Extrapyramidal clinical manifestations of parkinsonism are predominant in patients with BvFTD [117]. Apart from disorder of gait, other remarkable symptoms of iNPH are balance disturbances and psychomotor slowing [123]. Deficits in executive functions are core cognitive changes in both iNPH and BvFTD [116, 123].

Some authors have confirmed in large studies that the prevalence on FTD is 15 to 22/100,000 individuals [124, 125]. *The most prevalent age is among 60–69 years old with roughly 13% having onset when younger than age 50. Heavy genetic loading for FTD is the main cause of younger onset, with up to half of cases being familial and up to 40% autosomal dominant in nature* [99]*. Survival partially depends on the variant of FTD and ranges from 2 to 3 years after symptom onset when motor neuron symptoms are prominent and up to 12 years for the semantic dementia variant* [126].

A new of variant of FTD named phenocopy frontotemporal dementia (phFTD) has been described by Meijboom et al. recently [127]. It is an uncommon and poorly understood clinical syndrome characterized by similar clinical manifestations of BvFTD without abnormalities on MRI of the brain and without associated cognitive disorder. In contrast to phFTD, functional connectivity and white matter (WM) microstructural abnormalities have been observed in bvFTD. Some authors concluded that phFTD and bvFTD may belong to the same disease spectrum.

Canu et al. [128] reported some multiparametric MRI findings useful to differentiate early onset of AD (EOAD) from BvFTD based on the cortical thinning of the precuneus, posterior cingulate, superior and inferior parietal lobe, supramarginal, postcentral, and lingual gyri, and lateral occipital cortex bilaterally, and the left rostral and caudal middle frontal gyri seen in EOAD. Compared with the control group, the authors found a widespread pattern of cortical thinning involving all cerebral lobes, and compared to EOAD, BvFTD patients showed cortical thinning on the lateral orbitofrontal gyrus and temporal pole bilaterally, right entorhinal cortex, and right medial orbitofrontal gyrus. A severe cortical involvement is suggestive of EOAD, while a prominent white matter damage might be indicative of bvFTD.
