**4.2 Nutritional management**

The aim of nutritional management in patients with ALS is to prevent and/or treat malnutrition, to reduce the risk of aspiration, to prevent morbidity and mortality associated with malnutrition and dysphagia, and to improve quality of life. The nutritional approach in these patients includes the early detection of inefficient food intake, the need to adjust the consistency of the diet and, if oral feeding is not possible, the early indication of enteral nutrition by gastrostomy [12].

The nutritional approach modality is carried out according to the clinical situation, being conditioned in these patients by the safety and efficacy of swallowing and by the presence or absence of malnutrition.

#### *Dysphagia - New Advances*

In a malnourished patient or a patient being at nutritional risk, in whom oral feeding is possible, the first step is to optimize the diet and reduce the risk of aspiration [12].

The diet must be complete and cover the caloric-protein requirements of each patient. Energy requirements should be estimated as approx. 25–30 and 30 kcal/kg/day in ventilated and non-ventilated ALS patients, respectively [12]. Protein requirements should be calculated at a rate of 1–1.2 g/kg/day [44].

The diet composition for ALS patients does not differ from that of the general population with regard to the recommended macro- and micronutrients distribution [45–50]:


Dietary counseling and modification of food texture is a fundamental aspect of dysphagia treatment. Dietary modification alters the texture of both liquid and solid foods. These modifications should be based on each patient's swallowing capacity and must be regularly evaluated. Dietary modification allows achieving a better nutritional status and better quality of life in patients with special nutritional requirements.

There are multiple recommended methods for modifying the texture of solids and liquids. The *International Dysphagia Diet Standardization Initiative* (IDDSI) [51] establishes five levels of drink thickness (thin plus four levels of thickness) and five levels of food texture (regular plus four levels of modification):


Once the diagnosis of dysphagia has been made, the most appropriate solid and liquid food texture for the patient will be established, as well as the volume in which it should be administered.

Dietary modification includes high nutritional value ground or easy-to-swallow diets; texture modifiers, such as thickeners, gel waters or thickened beverages; and diet enhancers (food or nutrient modules) [52]. Also, certain foods should be avoided since they pose a high risk of choking, i.e., foods with double textures, dry or crunchy foods, sticky foods, foods that lose liquid when being chewed, and fibrous and/or filamentary foods.

Thickener modules are products with the ability to thicken, composed of modified starches or gums or a mixture of both, available as powder and with a

#### *Dysphagia of Neurological Origin – Amyotrophic Lateral Sclerosis DOI: http://dx.doi.org/10.5772/intechopen.101753*

neutral flavor. They are exclusively intended to increase the consistency of liquid foods. Thickeners composed exclusively of gums preserve the natural appearance of the liquid (unlike those that contain starches) and, therefore, improve the compliance of the patient with dysphagia.

If these dietary modifications do not allow maintaining an adequate nutritional state, oral nutritional supplements (ONS) will be administered, in addition to a modified diet.

Nutritional supplementation is recommended for ALS patients who do not cover their nutritional requirements with an enriched diet. However, there is insufficient data to affirm that oral nutritional supplementation can improve survival in ALS patients [12]. There are no specific formulas for patients with ALS. Hypercaloric formulas with fiber and high viscosity are generally recommended to prevent constipation and reduce the use of thickeners. Thickened ONS have been marketed in recent years and are suitable for patients with difficulties in swallowing, requiring a level 3 consistency or more.

All these measures, together with the general recommendations and the rehabilitative treatment of dysphagia, are aimed at optimizing safe oral intake. However, dysphagia in ALS patients is generally progressive. Thus, if dysphagia makes oral nutritional intake impossible or the patient is severely malnourished, enteral nutrition may be required. Enteral nutrition will preferably be administered by gastrostomy tube [12].

PEG is the most widely technique and is performed under endoscopic control. Its placement and use are well tolerated by the patient and allows them to meet their nutritional needs.

The timing of PEG placement is controversial.

However, there are studies that recommend the placement of a PEG in ALS patients when forced vital capacity is still greater than 50% [53], since a lower percentage would indicate a greater deterioration in lung function that could increase the risk of complications during the procedure. The American Academy of Neurology [54] recommends rejecting gastrostomy when the FVC is below 30% and considers other forms of palliative care. However, several studies show that gastrostomy could be performed safely in patients with insufficient respiratory function [55–57]. The current clinical guidelines [12] do not take a clear position and allow recommendation, respectively, rejection of gastrostomy based on FVC. The reason is that ALS patients with dysphagia, particularly those with primary bulbar involvement, may have poor spirometry performance due to orofacial muscle weakness.

However, early gastrostomy implantation prevents the development of disease complications and improves the quality of life of these patients [58] but has not clearly shown a benefit in patient survival [59]. However, patients who still maintain oral intake tend to be reluctant to place it early.

In any case, the timing of the PEG placement must be agreed with the patient and family, respecting their wishes [12].
