1.Preclinical symptoms
The first preclinical symptoms were only reported by Fletcher (1973) and others, but they have not received much attention so far, and these symptoms mainly include the following two aspects.
(1) abnormal sensation
The main manifestations are numbness, tingling, ankylosis and burning sensation at the joints of the affected limbs without any cause, mainly at the wrist and ankle, mostly intermittent or wandering at the beginning, and fixed at a later stage, with no obvious objective sensory abnormalities on routine neurological examination. In the early 1990s, we made a retrospective survey of 150 patients, and the result was that all of them had experienced abnormal sensation in the affected limb before the appearance of clinical symptoms of PD to varying degrees, and the abnormality could persist, but it was not in parallel with motor disorders, and the electrophysiological examination was mainly somatosensory, and the cortical evoked potentials had cortical delay and conduction delay and prolonged latency.
(2) Restless limbs and easy fatigue
In addition to subjective sensory abnormalities, about 1/2 of the patients had experienced indescribable discomfort such as soreness, swelling, numbness or pain in the affected limbs in the early stage, and this discomfort mostly occurred or was obvious when resting after exertion, and could be relieved after knocking or pounding, which is like the performance of restless leg syndrome. After exertion, slight tremors may appear in these areas, which are difficult to detect, and the general analgesics can be effective at the beginning of these symptoms, but after several months, they have no effect.
2. Clinical phase symptoms
There are obvious individual differences in the first symptoms, with some reports showing that subjective sensory abnormalities are 85%, tremor is 70.5%, muscle stiffness or slow movement is 19.7%, loss of dexterity and/or writing disorder is 12.6%, gait disorder is 11.5%, myalgia spasm and pain is 8.2%, mental disorders such as depression and anxiety are 4.4%, speech disorder is 3.8%, general weakness or muscle weakness was 2.7%, and drooling and mask face were 1.6% each.
(1) Static tremor
The mechanism is due to the regular and alternating uncoordinated activities of the affected and antagonistic muscle groups, which is often manifested at the distal end of the limb, starting from one side, with hand tremor of the upper limb being the most common, and in some patients starting from the knee of the lower limb, when accompanied by rotational components, thumb and finger rubbing-like tremor may appear. The frequency of tremor is usually 4-8Hz, appears at rest, stops when vigorous movements are made, intensifies when nervous, and disappears during sleep, and after several years, it may involve the upper and lower extremities of the same side or the opposite side. Some patients may have combined action or postural tremor.
(2) Myotonicity (rigidity)
Myotonicity is one of the main symptoms of PD, which is mainly due to the increased tension of the active and antagonistic muscles in balance. If the tremor is accompanied by a cogging sensation during passive movement, it is called “cogwheel-like tonus or tension”. The earliest occurrence of myotonia is in the affected wrist and ankle, especially after exertion, when the patient moves the wrist and ankle gently, the cogwheel-like tone can be increased.
The following clinical tests are useful in detecting mild myotonia.
①Make the patient move the contralateral limb, the myotonia of the examined limb can be more obvious.
(2) head dropping test: the patient is in the supine position, and the head often falls slowly when the pillow under the head is quickly withdrawn, instead of falling rapidly.
(③ make the patient put both elbows on the table, so that the forearm and the table into a vertical position, the two arms and wrist muscles as much as possible to relax, normal people at this time the wrist and forearm about 90 ° flexion, PD patients wrist more or less straight, as if the vertical road signs, called “road signs phenomenon”, elderly patients muscle ankylosis caused by joint pain, is the muscle tone Increased muscle tone causes joint pain, which is the result of increased muscle tone and obstruction of blood supply to the joint.
(3) Bradykinesia
The symptoms of bradykinesia include reduced random movements, including difficulty in initiation and bradykinesia, a series of characteristic symptoms of dyskinesia due to increased muscle tone and impaired postural reflexes, such as bradykinesia when getting up, turning over, walking and changing direction, reduced facial expression muscle activity, often double gaze, reduced transient eyes, masked face, difficulty in fine finger movements such as buttoning, tying shoelaces, etc., and the smaller the word is when writing, the smaller the word is when writing. The more you write, the smaller your writing becomes, which is called micrographia.
In the past, it was thought that the motor inability of PD was due to myotonicity, but in fact, there is no causal relationship between the two. It has been tentatively proved that the reduced motor and inability of PD is a very complicated symptom, which is mainly related to the function of the subcortical extrapyramidal drive or the disorder of the extrapyramidal downward motor activation device, because patients with motor inability can be operated. After treatment, myotonic symptoms improve significantly, but their motor frequency does not improve consistently as it does with dopa medication.
(4) Postural gait abnormalities
Postural dysreflexia is the main symptom that brings PD patients difficulty in life, it is second only to reduced movement or inability to move, the patient’s extremities, trunk and neck muscular ankylosis in a special flexion posture, head tilted forward, trunk prone flexion, upper limb elbow flexion, wrist extension, forearm induction, interphalangeal joint extension, thumb to palm; lower limb hip and knee joints are slightly bent, early lower limb dragging, gradually become a small gait. The lower limbs are slightly bent at the hip and knee joints, the lower limbs are dragging at the early stage, gradually become small gait, difficult to start, forward after starting, faster and faster, unable to stop or turn in time, called “panic gait” (festination), the upper limbs swinging when walking is reduced or disappeared, the trunk is stiff when turning, the trunk and head joint with small step turning, related to postural balance disorder leading to unstable center of gravity, the patient is afraid of falling. The postural disorder is aggravated with the progress of the disease, and in the late stage, it is difficult to get up from sitting and lying position. There is no clear explanation for the mechanism of this inherent postural reflex disorder in PD patients, and it is thought that the symptoms are mainly related to the damage of the efferent loop from the pallidum to the cortex via the thalamus.
(5) Other symptoms.
① Repeated tapping on the upper edge of the patient’s brow arch can induce more than one blink (Myerson’s sign), and the response is not sustained in normal subjects; there may be eyelid clonus (mild fluttering of the closed eyelid) or eyelid spasm (involuntary closure of the eyelid).
②Mouth, pharyngeal, and palate muscles are impaired in movement, resulting in slow speech, low monotone speech, salivation, etc. In severe cases, swallowing is difficult.
③Sebaceous glands and sweat glands are commonly hypersecreted, causing oily face, excessive sweating, obstinate constipation due to digestive tract motility disorders, and upright hypotension due to sympathetic nerve dysfunction.
Psychiatric symptoms include depression, anxiety, agitation, mild cognitive impairment and visual hallucinations in some patients, which are usually not severe.